OFFSET
0,2
COMMENTS
Never prime, as a(n) = (2n^4 + 4n^3 + 6n^2 + 4n + 1) * (n^8 + 4n^7 + 22n^6 + 52n^5 + 69n^4 + 56n^3 + 28n^2 + 8n + 1) Semiprime for n in {1, 2, 3, 6, 14, 16, 36, 87, 97, 109, 110, 119, 121, 163, 195, ...}. - Jonathan Vos Post, Aug 26 2011
REFERENCES
B. K. Teo and N. J. A. Sloane, Magic numbers in polygonal and polyhedral clusters, Inorgan. Chem. 24 (1985), 4545-4558.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..10000
FORMULA
G.f.: -(x^10 + 4082*x^9 + 474189*x^8 + 9713496*x^7 + 56604978*x^6 + 105907308*x^5 + 56604978*x^4 + 9713496*x^3 + 474189*x^2 + 4082*x + 1)*(1+x)^2 / (x-1)^13. - R. J. Mathar, Aug 27 2011
MATHEMATICA
Total/@Partition[Range[0, 20]^12, 2, 1] (* Harvey P. Dale, May 09 2018 *)
PROG
(Magma) [(n+1)^12+n^12: n in [0..20]]; // Vincenzo Librandi, Aug 27 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved