A213107 Primes p such that 2p^2-1, 3p^2-2, 4p^2-3, and 5p^2-4 are also prime.

17569, 43781, 70321, 229561, 251231, 426131, 426551, 453289, 635051, 727201, 729791, 741709, 944689, 981091, 1015309, 1078081, 1128761, 1228429, 1231229, 1282961, 1289149, 1302349, 1351099, 1723481, 1763159, 1823779, 2078339, 2260889, 2336519, 2357879

Offset

1,1

Comments

Subsequence of A213079: a(1) = 17569 = A213079(10) =A213078(44)= A106483(389) = A000040(2019).

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..740

Mathematica

Select[Prime[Range[200000]], PrimeQ[2 #^2 - 1] && PrimeQ[3 #^2 - 2] && PrimeQ[4 #^2 - 3] && PrimeQ[5 #^2 - 4] &] (* T. D. Noe, Jun 06 2012 *)

Prog

(Magma) [p: p in PrimesUpTo(2500000) | forall{i*p^2-i+1: i in [2..5] | IsPrime(i*p^2-i+1)}]; // Vincenzo Librandi, Apr 08 2013

Crossrefs

Cf. A000040, A106483, A213078, A213079.

Sequence in context: A049521 A203963 A253403 * A167190 A203353 A273035

Adjacent sequences: A213104 A213105 A213106 * A213108 A213109 A213110

Keyword

nonn,easy

Author

Zak Seidov, Jun 05 2012

Status

approved