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A033299 Smallest safe prime ((p-1)/2 is also prime) > n. 4
5, 5, 5, 5, 7, 7, 11, 11, 11, 11, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 47, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 59, 83, 83, 83, 83, 83, 83, 83, 83, 83 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Michael S. Branicky, Table of n, a(n) for n = 1..10000

MAPLE

with(numtheory); safeprime(n);

PROG

(Python)

from sympy import isprime, nextprime

def a(n):

  p = nextprime(n)

  while not isprime((p-1)//2): p = nextprime(p)

  return p

print([a(n) for n in range(1, 68)]) # Michael S. Branicky, May 05 2021

CROSSREFS

Sequence in context: A139259 A105444 A240233 * A293982 A071577 A003870

Adjacent sequences:  A033296 A033297 A033298 * A033300 A033301 A033302

KEYWORD

nonn,changed

AUTHOR

N. J. A. Sloane.

EXTENSIONS

a(57) and beyond from Michael S. Branicky, May 05 2021

STATUS

approved

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Last modified May 16 18:13 EDT 2021. Contains 343949 sequences. (Running on oeis4.)