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Revision History for A360081

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A360081

Smallest k such that 2^(3*2^n) + k is a safe prime.
(history; published version)

#21 by Alois P. Heinz at Fri Jan 27 15:26:59 EST 2023

STATUS

proposed

approved

#20 by Chai Wah Wu at Fri Jan 27 15:11:22 EST 2023

STATUS

editing

proposed

#19 by Chai Wah Wu at Fri Jan 27 15:11:06 EST 2023

PROG

if isprime((k:=(i<<1)+1):

return k-(m<<1)+1 # Chai Wah Wu, Jan 27 2023

STATUS

proposed

editing

#18 by Jon E. Schoenfield at Fri Jan 27 14:02:52 EST 2023

STATUS

editing

proposed

#17 by Jon E. Schoenfield at Fri Jan 27 14:02:32 EST 2023

COMMENTS

a(n) == 3 (mod 4). - Chai Wah Wu, Jan 27 2023

STATUS

proposed

editing

Discussion

Fri Jan 27

14:02

Jon E. Schoenfield: (per the Style Sheet)

#16 by Chai Wah Wu at Fri Jan 27 13:35:10 EST 2023

STATUS

editing

proposed

#15 by Chai Wah Wu at Fri Jan 27 13:35:03 EST 2023

PROG

return k-(m<<1)+1 # Chai Wah Wu, Jan 27 2023

#14 by Chai Wah Wu at Fri Jan 27 13:34:52 EST 2023

PROG

(Python)

from sympy import isprime, nextprime

def A360081(n):

m = 1<<3*(1<<n)-1

i = m

while i:=nextprime(i):

if isprime((k:=i<<1)+1):

return k-(m<<1)+1 # Chai Wah Wu, Jan 27 2023

#13 by Chai Wah Wu at Fri Jan 27 13:32:02 EST 2023

COMMENTS

a(n) == 3 mod 4. - Chai Wah Wu, Jan 27 2023

STATUS

approved

editing

#12 by Alois P. Heinz at Thu Jan 26 21:20:57 EST 2023

STATUS

proposed

approved