S000793


Prime numbers that are the sum of consecutive heptagonal numbers.

7, 59, 89, 107, 193, 307, 337, 449, 521, 619, 863, 1009, 1031, 1051, 1657, 3067, 3433, 4217, 4561, 5011, 5351, 5849, 6163, 6553, 7297, 7541, 8081, 9769, 11617, 11971, 12601, 13679, 13723, 14327, 16361, 16937, 18121, 19699, 20051, 25847, 27529, 29033, 29347

1

S000793

The only prime heptagonal number is 7, the first term. Other terms are the sum of 2, 3, or 6 consecutive heptagonal numbers.

T. D. Noe, Plot of 1000 terms

T. D. Noe, Table of 1000 terms

Wikipedia, Polygonal number

(Mma) nn = 400; f = 7; s = Table[k ((f - 2) k - (f - 4))/2, {k, nn}]; t = Table[Select[Plus @@@ Partition[s, n, 1], PrimeQ], {n, 6}]; mx = Min[Select[Max /@ Rest[t], # > 0 &]]; Select[Union[Flatten[t]], # <= mx &]

Cf. A163251 (squares), S000790-S000799.

nonn

T. D. Noe, Dec 11 2015

© Tony D Noe 2014-2015