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A007521
Primes of the form 8k + 5.
(Formerly M3828)
51
5, 13, 29, 37, 53, 61, 101, 109, 149, 157, 173, 181, 197, 229, 269, 277, 293, 317, 349, 373, 389, 397, 421, 461, 509, 541, 557, 613, 653, 661, 677, 701, 709, 733, 757, 773, 797, 821, 829, 853, 877, 941, 997, 1013, 1021, 1061, 1069, 1093, 1109, 1117, 1181, 1213
OFFSET
1,1
COMMENTS
Primes of the form 4x^2 - 4xy + 5y^2 with x and y nonnegative. - T. D. Noe, May 08 2005
Prime numbers 2k+1 with k even such that 2k+1 | 2^k+1. - Hilko Koning, Jan 21 2022
REFERENCES
Milton Abramowitz and Irene A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 870.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Ray Chandler, Table of n, a(n) for n = 1..10000 (first 1000 terms from T. D. Noe)
Milton Abramowitz and Irene A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
MATHEMATICA
Select[8Range[0, 160] + 5, PrimeQ] (* Harvey P. Dale, Apr 22 2011 *)
PROG
(PARI) list(lim)=select(n->n%8==5, primes(primepi(lim))) \\ Charles R Greathouse IV, Jul 25 2011
(Haskell)
a007521 n = a007521_list !! (n-1)
a007521_list = filter ((== 1). a010051) a004770_list
-- Reinhard Zumkeller, Aug 17 2012
(Magma) [p: p in PrimesUpTo(2000) | p mod 8 eq 5]; // Vincenzo Librandi, Jun 26 2014
(Python)
from sympy import isprime
print(list(filter(isprime, range(5, 1214, 8)))) # Michael S. Branicky, May 13 2021
CROSSREFS
Cf. A010051.
Subsequence of A004770; see also A045323.
Sequence in context: A347836 A100877 A261580 * A294919 A213050 A216822
KEYWORD
nonn,easy,nice
STATUS
approved

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