A015501 a(0)=1, a(1)=12, a(n) = sum_{k=0}^{k=n-1} 12^k a(k).

1, 12, 145, 21025, 36352225, 753836089825, 187579295739424225, 560108963388484644486625, 20069717395324174580677650054625, 8629611143951908451324039380459800198625

Offset

0,2

Links

Table of n, a(n) for n=0..9.

Formula

a(n) = (12^(n-2) + 1) * a(n-1). - Vincenzo Librandi, Nov 11 2012

Prog

(Magma) I:=[1, 12, 145]; [n le 3 select I[n] else (12^(n-2)+1)*Self(n-1): n in [1..15]]; // Vincenzo Librandi, Nov 11 2012

Crossrefs

Sequence in context: A041061 A174227 A041266 * A039493 A196454 A329013

Adjacent sequences: A015498 A015499 A015500 * A015502 A015503 A015504

Keyword

nonn,easy

Author

Olivier Gérard

Status

approved