mersenneforum.org Search Results
 Register FAQ Search Today's Posts Mark Forums Read

 Showing results 1 to 25 of 30 Search took 0.01 seconds. Search: Posts Made By: toferc
 Forum: Miscellaneous Math 2004-11-23, 22:14 Replies: 58 Views: 4,193 Posted By toferc The cover of the book still has the "The", as... The cover of the book still has the "The", as does the Library of Congress listing... Oh, and shaxper... every number you ever do any computing with will be rational.
 Forum: Math 2003-08-08, 11:43 Replies: 28 Views: 3,710 Posted By toferc Consider f(x) = 1.5x + 2. f(0) = 2 (prime) ... Consider f(x) = 1.5x + 2. f(0) = 2 (prime) f(1*2) = 5 (not divisible by 2)
 Forum: Miscellaneous Math 2003-08-06, 21:15 Replies: 33 Views: 4,885 Posted By toferc This seems to deserve proof, so here it is: ... This seems to deserve proof, so here it is: Theorem 1: The sum of the decimal digits of an integer x > 0 (sdd(x)) is congruent to x modulo 9. Proof: Observe that sdd(1) = 1. let d(0,k),...
 Forum: Miscellaneous Math 2003-08-06, 19:54 Replies: 33 Views: 4,885 Posted By toferc That's why it's a counterexample :) That's why it's a counterexample :)
 Forum: Miscellaneous Math 2003-08-06, 19:31 Replies: 33 Views: 4,885 Posted By toferc Counterexample: 2^10*(2^11-1) = 2096128 Counterexample: 2^10*(2^11-1) = 2096128
 Forum: Puzzles 2003-08-06, 19:18 Replies: 24 Views: 1,391 Posted By toferc In that case, $5.03 In that case,$5.03
 Forum: Miscellaneous Math 2003-08-06, 19:07 Replies: 33 Views: 4,885 Posted By toferc [/quote] n = 2: 2^1 * (2^2-1) = 6 n = 3:... [/quote] n = 2: 2^1 * (2^2-1) = 6 n = 3: 2^2 * (2^3-1) = 28 n = 5: 2^4 * (2^5-1) = 496 etc. The definition of a perfect number is that it is equal to the sum of all of its factors. In...
 Forum: Puzzles 2003-08-06, 17:55 Replies: 24 Views: 1,391 Posted By toferc Assuming that the shopkeeper gave change for the... Assuming that the shopkeeper gave change for the counterfeit $5, all of the other facts are irrelevant. The pirate received$5 worth of goods and cash in exchange for a worthless bill. The...
 Forum: Puzzles 2003-08-03, 19:20 Replies: 15 Views: 1,058 Posted By toferc The whole point of exercises like this is that... The whole point of exercises like this is that when testing for a rare condition, false positives can (and often do) outnumber true positives, even when the accuracy on a single test is high. The...
 Forum: Puzzles 2003-08-03, 19:18 Replies: 15 Views: 1,058 Posted By toferc You misplaced a decimal. The calculation should... You misplaced a decimal. The calculation should read [code:1] 0.1 99 ---- x ----- 60 100 9.9 9.9...
 Forum: Puzzles 2003-08-03, 15:50 Replies: 15 Views: 1,058 Posted By toferc The statement of the problem was The... The statement of the problem was The population of the UK, along with the number of AIDS sufferers in the UK, is exactly the information you need to answer the question.
 Forum: Puzzles 2003-07-15, 20:29 Replies: 15 Views: 2,306 Posted By toferc Just what this forum needed, the 500th "Monty... Just what this forum needed, the 500th "Monty Hall" flamewar. I personally have been involved in at least a half-dozen of these. TravisT has it right, but I'll try to say it another way for...
 Forum: Hardware 2003-06-24, 16:51 Replies: 847 Views: 155,489 Posted By toferc Intel(R) Xeon(TM) CPU 3.06GHz CPU speed:... Intel(R) Xeon(TM) CPU 3.06GHz CPU speed: 3056.78 MHz CPU features: RDTSC, CMOV, PREFETCH, MMX, SSE, SSE2 L1 cache size: 8 KB L2 cache size: 512 KB L1 cache line size: 64 bytes L2 cache line...
 Forum: Lounge 2003-06-20, 17:15 Replies: 2 Views: 1,254 Posted By toferc Unless I am mistaken, Vincent Edmondson was one... Unless I am mistaken, Vincent Edmondson was one of the two people responsible for the GIMPS participation at Central Missouri State University, under the account name 'curtisc'. ...
 Forum: Puzzles 2003-06-19, 20:27 Replies: 28 Views: 4,497 Posted By toferc I used cosine rule and double differentiation as... I used cosine rule and double differentiation as well, though I later thought polar coordinates might be more convenient, or elegant. Been too busy to post my solution or find a new problem; glad...
 Forum: Puzzles 2003-06-09, 23:04 Replies: 28 Views: 4,497 Posted By toferc Thought I'd allow some time for others before... Thought I'd allow some time for others before posting the spoiler :)
 Forum: Puzzles 2003-06-09, 22:44 Replies: 28 Views: 4,497 Posted By toferc Clock puzzle sqrt(7)
 Forum: Math 2002-11-23, 03:54 Replies: 5 Views: 2,121 Posted By toferc Never mind. Never mind.
 Forum: Math 2002-11-04, 12:44 Replies: 7 Views: 1,489 Posted By toferc Re: Mersenne's on Ulams spiral This form can be rewritten as 2^k - 1, where k is odd and greater than one, thus these numbers form a subset of the Mersenne numbers. It is known that 2^k - 1 is prime only if k is prime, therefore...
 Forum: Software 2002-10-11, 02:49 Replies: 60 Views: 5,359 Posted By toferc Maybe you know something I don't know... As far... Maybe you know something I don't know... As far as I know, Intel was founded in 1968, whereas Weitek was founded in 1981.
 Forum: PrimeNet 2002-10-09, 05:48 Replies: 33 Views: 5,826 Posted By toferc OK, I can't resist putting my two cents' worth... OK, I can't resist putting my two cents' worth in. I've been thinking about this one for some time. I've noticed that 1 P90 CPU year = 1.04*10^15 floating point ops based on the line from the IPS. ...
 Forum: PrimeNet 2002-09-26, 04:01 Replies: 228 Views: 17,755 Posted By toferc Over the years, the Primenet server has proven to... Over the years, the Primenet server has proven to be both robust and stable. Reimplementing its functionality and maintaining a server are nontrivial tasks, to say the least. I'd like to know if...
 Forum: Math 2002-09-26, 02:00 Replies: 17 Views: 4,299 Posted By toferc Woops :surprised:ops:. I can't believe I said... Woops :surprised:ops:. I can't believe I said that. Thank you for clearing that up. Tofer
 Forum: Math 2002-09-15, 03:51 Replies: 13 Views: 2,598 Posted By toferc jocelynl has got it quite right. It might help... jocelynl has got it quite right. It might help to look at the GIMPS home page quickie description of the algorithm at http://www.mersenne.org/math.htm under "Trial Factoring". Chris...
 Forum: Math 2002-09-14, 18:05 Replies: 17 Views: 4,299 Posted By toferc The only restriction on the number k is that it... The only restriction on the number k is that it is a nonnegative integer. For example, M11 = 2^11 - 1 = 2047 has the divisors 1, 23, 87 and 2047. 1 = 2*0*11 + 1 (k=0) 23 = 2*1*11 + 1 (k=1) 87 =...
 Showing results 1 to 25 of 30

All times are UTC. The time now is 21:45.

Wed Apr 21 21:45:52 UTC 2021 up 13 days, 16:26, 0 users, load averages: 2.39, 2.15, 1.98