OFFSET
0,2
COMMENTS
Never prime, as a(n) = (2n + 1) * (n^12 + 6n^11 + 36n^10 + 125n^9 + 295n^8 + 496n^7 + 610n^6 + 553n^5 + 367n^4 + 174n^3 + 56n^2 + 11n + 1). Semiprime for n in {1, 8, 15, 21, 86, 135, 141, 249, 260, 278, 323, 326, 363, ...}. - Jonathan Vos Post, Aug 26 2011
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..10000
B. K. Teo and N. J. A. Sloane, Magic numbers in polygonal and polyhedral clusters, Inorgan. Chem. 24 (1985), 4545-4558.
MAPLE
MATHEMATICA
Table[(n + 1)^13 + n^13, {n, 0, 20}] (* Wesley Ivan Hurt, Apr 01 2014 *)
PROG
(Magma) [(n+1)^13+n^13: n in [0..20]]; // Vincenzo Librandi, Aug 27 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved