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A101796
Primes of the form 8*k-1 such that 4*k-1, 16*k-1 and 32*k-1 are also primes.
7
359, 719, 5399, 7079, 24239, 34319, 54959, 107279, 115679, 126839, 142799, 149399, 164999, 175079, 202799, 214559, 215399, 225839, 244199, 245639, 253679, 254279, 266999, 278879, 333479, 335519, 459479, 507359, 508559
OFFSET
1,1
LINKS
FORMULA
a(n) = 8*A101794(n) - 1 = 2*A101795(n) + 1. - Amiram Eldar, May 13 2024
EXAMPLE
4*45-1 = 179, 8*45-1 = 359, 16*45-1 = 719 and 32*45-1 = 1439 are primes, so 359 is a term.
MATHEMATICA
8 * Select[Range[10^5], And @@ PrimeQ[2^Range[2, 5]*# - 1] &] - 1 (* Amiram Eldar, May 13 2024 *)
PROG
(PARI) is(k) = if(k % 8 == 7, my(m = k\8 + 1); isprime(4*m-1) && isprime(8*m-1) && isprime(16*m-1) && isprime(32*m-1), 0); \\ Amiram Eldar, May 13 2024
CROSSREFS
Subsequence of A007522 and A101792.
Subsequence: A101996.
Sequence in context: A344286 A142381 A054826 * A175537 A142852 A158307
KEYWORD
easy,nonn
AUTHOR
Douglas Stones (dssto1(AT)student.monash.edu.au), Dec 16 2004
STATUS
approved