A285790 Primes equal to a hexagonal number plus 1.

2, 7, 29, 67, 191, 277, 379, 631, 947, 1129, 1327, 2017, 2557, 2851, 4561, 4951, 5779, 6217, 8647, 9181, 12721, 13367, 14029, 15401, 16111, 17579, 20707, 21529, 22367, 24091, 24977, 31627, 36857, 37951, 42487, 43661, 44851, 47279, 53629, 58997, 64621, 66067

Offset: 1

Author

Colin Barker, Apr 26 2017

Keywords

• nonn

Comments

Apart from the leading 2 the same as A176616. - R. J. Mathar, Apr 27 2017

Primes in A130883. - Omar E. Pol, Apr 27 2017

Links

• Colin Barker, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000040, A000384, A002496, A055469, A285789, A285791, A176616, A285792.

Programs

Mathematica

Select[PolygonalNumber[6,Range[200]]+1,PrimeQ] (* Harvey P. Dale, Jun 16 2022 *)

PARI

pg(m, n) = (n^2*(m-2)-n*(m-4))/2 \\ n-th m-gonal number
maxk=300; L=List(); for(k=1, maxk, if(isprime(p=pg(6, k) + 1), listput(L, p))); Vec(L)