Special whole numbers... - Page 9

Kevin · 2003-08-26, 11:12

January 1st, 1801 (1801 01 01) was the first day in the 19th century.

78,501

Uncwilly · 2003-08-26, 13:10

Cheesehead: 20030831 is not only next Sunday, it is the next date that is prime. :)

Again: 78,501

nomadicus · 2003-08-26, 15:51

Quote:

THAT'S IT! nomadicus IS TELLING US THAT 2^934579438317757 - 1 IS NOT ONLY PRIME BUT ALSO PALINDROMIC IN BOTH BASE 8 AND BASE 11 !!!! WOW!! Way to go, nomadicus!

Geez. I'm gone for a couple of days and I learn so much about what I didn't intend. You guys are good.

You guys are going to kill me, but I made a typo (I never should have done this from memory). Palindromic is correct but the number should have been 99999999299999999. (The number before that is 99999997879999999 and I substituted the 8 for the 2, etc. Oh boy!)

Sorry about that. If someone hasn't already, I'll explain myself as soon as I can find my way out of humility hall (oblique reference to the original Adventure game after having been crushed by the Hall of the Moutain King's dragon -- Do I even remember that correctly???).

-=- john

ops:

eepiccolo · 2003-08-26, 17:26

Holy crap! It's amazing what one little typo can do!

Uncwilly · 2003-08-27, 14:31

I'll take a couple of swipes at 78501:

1) It is the ZIP code for McAllen, Texas

2) 137 * 573 = 191 * 411 = 78501

Is that what you wanted Kevin?

[Edit: Provisional next number: 90210]

nomadicus · 2003-08-27, 15:31

Quote:

Palindromic is correct but the number should have been 99999999299999999.

It is also the last signed 64bit palprime completeing a series of 17 digits. You can't complete all the 19 digit palprimes unless you swtich to unsigned 64-bit quantities (and they take forever to factor -- a few decades on a alpha last time I calculated the timings of my unoptimized C code). In general, I find 64bit palprimes interesting. :)

cheesehead · 2003-08-28, 00:21

January 1, 1801 was also the date on which Italian astronomer Giuseppe Piazzi made the first discovery of an asteroid, which he named Ceres.

Kevin · 2003-08-28, 01:15

Well, that wasn't what I had in mind, but I don't think that's ever stopped us from moving on before.... If you want a hint, think of prime numbers.

[BTW, I'll say yours is the area code for Beverly Hills :) ]

Pi Rho · 2003-08-28, 20:28

Ooh! Ooh! I know!

Number of primes less than or equal to 1,000,037

353,701

Kevin · 2003-08-29, 01:03

Actually it's number of primes less that 1,000,000 , but close enough.....

cheesehead · 2003-08-29, 07:09

According to The Nth Prime Page at http://www.math.princeton.edu/~arbooker/nthprime.html pi(1000000) = 78498 and the 78,501st prime is 1,000,037.

(BTW, if you hurry, you can be the 80,000th person to visit that page.)

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2003-08-26, 11:12	#89
Kevin Aug 2002 Ann Arbor, MI 433 Posts	January 1st, 1801 (1801 01 01) was the first day in the 19th century. 78,501

2003-08-26, 13:10	#90
Uncwilly 6809 > 6502 """"""""""""""""""" Aug 2003 101×103 Posts 5·19·103 Posts	Cheesehead: 20030831 is not only next Sunday, it is the next date that is prime. :) Again: 78,501

2003-08-26, 17:26	#92
eepiccolo Dec 2002 Frederick County, MD 370₁₀ Posts	Holy crap! It's amazing what one little typo can do!

2003-08-27, 14:31	#93
Uncwilly 6809 > 6502 """"""""""""""""""" Aug 2003 101×103 Posts 10011000111001₂ Posts	I'll take a couple of swipes at 78501: 1) It is the ZIP code for McAllen, Texas 2) 137 * 573 = 191 * 411 = 78501 Is that what you wanted Kevin? [Edit: Provisional next number: 90210]

2003-08-28, 00:21	#95
cheesehead "Richard B. Woods" Aug 2002 Wisconsin USA 7692₁₀ Posts	January 1, 1801 was also the date on which Italian astronomer Giuseppe Piazzi made the first discovery of an asteroid, which he named Ceres.

2003-08-28, 01:15	#96
Kevin Aug 2002 Ann Arbor, MI 433₁₀ Posts	Well, that wasn't what I had in mind, but I don't think that's ever stopped us from moving on before.... If you want a hint, think of prime numbers. [BTW, I'll say yours is the area code for Beverly Hills :) ]

2003-08-28, 20:28	#97
Pi Rho Sep 2002 101100₂ Posts	Ooh! Ooh! I know! Number of primes less than or equal to 1,000,037 353,701

2003-08-29, 01:03	#98
Kevin Aug 2002 Ann Arbor, MI 433 Posts	Actually it's number of primes less that 1,000,000 , but close enough.....

2003-08-29, 07:09	#99
cheesehead "Richard B. Woods" Aug 2002 Wisconsin USA 2²×3×641 Posts	According to The Nth Prime Page at http://www.math.princeton.edu/~arbooker/nthprime.html pi(1000000) = 78498 and the 78,501st prime is 1,000,037. (BTW, if you hurry, you can be the 80,000th person to visit that page.)