A276264 Centered 25-gonal primes.

151, 251, 701, 1951, 3001, 4751, 10151, 12401, 16651, 19501, 28201, 29401, 33151, 38501, 39901, 45751, 56951, 63901, 65701, 81001, 87151, 95701, 104651, 114001, 136501, 144451, 147151, 158201, 178501, 181501, 193751, 219451, 232901, 257401, 275651, 290701, 318001, 322001

Offset

1,1

Comments

Primes of the form (25*k^2 + 25*k + 2)/2.

Numbers k such that (25*k^2 + 25*k + 2)/2 is prime: 3, 4, 7, 12, 15, 19, 28, 31, 36, 39, 47, 48, 51, 55, 56, 60, 67, 71, 72, 80, 83, 87, 91, ...

Links

Robert Israel, Table of n, a(n) for n = 1..10000

OEIS Wiki, Centered polygonal numbers

Eric Weisstein's World of Mathematics, Centered Polygonal Number

Index entries for sequences related to centered polygonal numbers

Maple

select(isprime, [seq((25*k^2+25*k+2)/2, k=1..200)]); # Robert Israel, Sep 01 2016

Mathematica

Intersection[Table[(25 k^2 + 25 k + 2)/2, {k, 0, 1000}], Prime[Range[28000]]]

Prog

(PARI) lista(nn) = for(n=1, nn, if(isprime(p=(25*n^2 + 25*n + 2)/2), print1(p, ", "))); \\ Altug Alkan, Aug 26 2016

Crossrefs

Cf. A000040, A262221.

Cf. centered k-gonal primes listed in A276261.

Sequence in context: A334931 A059858 A152310 * A070182 A100200 A142575

Adjacent sequences: A276261 A276262 A276263 * A276265 A276266 A276267

Keyword

nonn,changed

Author

Ilya Gutkovskiy, Aug 26 2016

Status

approved