0,2

Can never be prime, as a(n) = (2n^8 + 8n^7 + 28n^6 + 56n^5 + 70n^4 + 56n^3 + 28n^2 + 8n + 1) * (n^16 + 8n^15 + 92n^14 + 504n^13 + 1750n^12 + 4312n^11 + 7980n^10 + 11432n^9 + 12869n^8 + 11440n^7 + 8008n^6 + 4368n^5 + 1820n^4 + 560n^3 + 120n^2 + 16n + 1). [Jonathan Vos Post, Aug 28 2011]

B. K. Teo and N. J. A. Sloane, Magic numbers in polygonal and polyhedral clusters, Inorgan. Chem. 24 (1985), 4545-4558.

Vincenzo Librandi, Table of n, a(n) for n = 0..10000

Total/@Partition[Range[0, 10]^24, 2, 1] (* Harvey P. Dale, Nov 23 2013 *)

(Magma) [(n+1)^24+n^24: n in [0..20]]; // Vincenzo Librandi, Aug 28 2011

Cf. A010812, A036100, A036101.

Sequence in context: A017580 A017711 A013972 * A230636 A283029 A250933

Adjacent sequences: A036099 A036100 A036101 * A036103 A036104 A036105

nonn,easy

approved