Posts that seem less than useless, or something like that

[cmd]

sm'°°-'2
ar-|ecch!n°
( t!tle °f mus!c !t )

::

[science_man_88]

Originally Posted by cmd

sm'°°-'2
ar-|ecch!n°
( t!tle °f mus!c !t )

::

So even mathematicians can fail epically.

[cmd]

Originally Posted by science_man_88

So even mathematicians can fail epically.

"being mathematical" label for human
pure mathematics is precise science ...
Who invented "math person"?

self-reference be dangerous

us (for example) non-mathematical ... that lie true ?

see here

[cmd]

hi (say) 33

en
it

!t !t !t| -||_|rra

[cmd]

Our little curiosity,
who have achieved "www" Don
since he posted in Mersennemforum and that it does not say ( post 1 )
GIMPS power to know first ?



( where it was from 1999 to yesterday ... on another celestial body ? )

::

[cmd]

we like_u

[science_man_88]

Originally Posted by Prime95

I need some code that efficiently (on Intel this means relatively short chunk of code with no branches that are hard to predict) returns the index of a randomly selected set bit in a 64-bit value.

Psuedo code:

int64 t;

cnt = POPCNT (t)
i = random value between 0 and cnt
while (i--) use BSF to find a set bit, then clear that set bit
return BSF(t)

POPCNT is an Intel assembly code instruction to count the number of set bits in a register
BSF is bit-scan-forward, it returns the index of the first set bit in a register


Clever bit-twiddling suggestions are welcome!

Well if I knew how to get PARI's random function to return only integers ( I may have a way), you could use

i=random(#<vector>);return(<vector>[i])

but I doubt this is efficient. I'll see what else I can come up with in PARI or ASM(using my book).

[cmd]

[360] prp

n

sm88?

[cmd]

Originally Posted by EdH

The page on Trial Factoring has the following:

"The simplest approach is to already have available a supply of small prime numbers to use as trial divisors."

I would like to suggest a slight change, in that as it now reads, it could be interpreted as suggesting that only some of the smaller prime numbers are needed, when in fact, all primes up to the square root+1 are needed.

Suggestions/Comments?

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2^40=4^20=16^10=256^5 .. (1099511627776+1)/257=(4278255361)prime --- [ edb ]

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est_art?

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b-a-u-b-a-u