A121292 a(n) = Bell(3*n+1).

1, 15, 877, 115975, 27644437, 10480142147, 5832742205057, 4506715738447323, 4638590332229999353, 6160539404599934652455, 10293358946226376485095653, 21195039388640360462388656799, 52868366208550447901945575624941, 157450588391204931289324344702531067

Offset

0,2

Links

Andrew Howroyd, Table of n, a(n) for n = 0..50

Formula

E.g.f.: exp(-1)*Sum_{n>=0} n*exp(n^3*x)/n!.

Mathematica

Table[ BellB[3*n + 1], {n, 0, 10}]  (* Jean-François Alcover, Dec 13 2012 *)

Prog

(PARI) a(n)={my(k=3*n+1); k!*polcoef(exp(exp(x + O(x*x^k)) - 1), k)} \\ Andrew Howroyd, Jan 08 2020

Crossrefs

Cf. A000110, A070906.

Sequence in context: A223818 A208349 A358802 * A208304 A258796 A232364

Adjacent sequences: A121289 A121290 A121291 * A121293 A121294 A121295

Keyword

easy,nonn

Author

Vladeta Jovovic, Aug 24 2006

Extensions

Terms a(11) and beyond from Andrew Howroyd, Jan 08 2020

Status

approved