A208177 Primes of the form 128*k + 1.

257, 641, 769, 1153, 1409, 2689, 3329, 3457, 4481, 4993, 6529, 7297, 7681, 7937, 9473, 9601, 9857, 10369, 10753, 11393, 11777, 12161, 12289, 13313, 13441, 13697, 14081, 14593, 15233, 15361, 16001, 17921, 18049, 18433, 19073, 19457, 19841, 20353, 21121, 21377

Offset: 1

Author

Bruno Berselli, Feb 25 2012

Keywords

• nonn
• easy

Comments

Odd primes p such that -1 is a 64th power mod p. - Eric M. Schmidt, Mar 27 2014

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A065091, A002144, A007519, A094407, A133870, A142925, A208178, A076339.

Programs

Haskell

a208177 n = a208177_list !! (n-1)
a208177_list = filter ((== 1) . a010051) [1,129..]
-- Reinhard Zumkeller, Mar 06 2012

Magma

[ p: p in PrimesUpTo(22000) | p mod 128 eq 1 ];

Mathematica

Select[128 Range[167] + 1, PrimeQ]

PARI

for(n=1,167,r=128*n+1; if(isprime(r), print1(r", ")));

Formula

a(n) ~ 64n log n. - Charles R Greathouse IV, Nov 01 2022