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A101798
Primes of the form 32*k-1 such that 4*k-1, 8*k-1 and 16*k-1 are also primes.
6
1439, 2879, 21599, 28319, 96959, 137279, 219839, 429119, 462719, 507359, 571199, 597599, 659999, 700319, 811199, 858239, 861599, 903359, 976799, 982559, 1014719, 1017119, 1067999, 1115519, 1333919, 1342079, 1837919, 2029439, 2034239
OFFSET
1,1
LINKS
FORMULA
a(n) = 32*A101794(n) - 1 = 8*A101795(n) + 7 = 4*A101796(n) + 3 = 2*A101797(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 1439 is a term.
MATHEMATICA
32 * Select[Range[10^5], And @@ PrimeQ[2^Range[2, 5]*# - 1] &] - 1 (* Amiram Eldar, May 13 2024 *)
PROG
(PARI) is(k) = if(k % 32 == 31, my(m = k\32 + 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 A127578.
Subsequence: A101998.
Sequence in context: A227494 A352249 A351677 * A081426 A101998 A174277
KEYWORD
easy,nonn
AUTHOR
Douglas Stones (dssto1(AT)student.monash.edu.au), Dec 16 2004
STATUS
approved