A036095 - OEIS

A036095

Centered cube numbers: a(n) = (n+1)^17 + n^17.

1, 131073, 129271235, 17309009347, 780119322309, 17689598897861, 249557173431943, 2484430327672455, 18928981513351817, 116677181699666569, 605447028499293771, 2724058135239730763, 10869027026121774925

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

COMMENTS

Never prime, as a(n) = (2n + 1) * (n^16 + 8n^15 + 64n^14 + 308n^13 + 1036n^12 + 2576n^11 + 4900n^10 + 7274n^9 + 8518n^8 + 7896n^7 + 5776n^6 + 3300n^5 + 1444n^4 + 468n^3 + 106n^2 + 15n + 1). Semiprime for n in {1, 5, 21, 29, 33, ...}. - Jonathan Vos Post, Aug 27 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

PROG

(Magma) [(n+1)^17+n^17: n in [0..20]]; // Vincenzo Librandi, Aug 28 2011

CROSSREFS

Cf. A000040, A036085, A036087, A036088, A036089, A036090, A036091, A036092, A036093, A100267, A154535, A100266, A152913, A194155, A194185, A194216.

Sequence in context: A323546 A017697 A013965 * A384373 A214290 A187939

Adjacent sequences: A036092 A036093 A036094 * A036096 A036097 A036098

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

STATUS

approved