A015497 a(0)=1, a(1)=9, a(n) = sum_{k=0}^{k=n-1} 9^k a(k).

1, 9, 82, 6724, 4908520, 32209708240, 1901983271572000, 1010793793810766824000, 4834596391983083396187280000, 208113526867898819658489702096160000, 80627444554789525982513713046048334318400000

Offset

0,2

Links

Table of n, a(n) for n=0..10.

Formula

a(n) = (9^(n-2) + 1) * a(n-1). - Vincenzo Librandi, Nov 11 2012

Prog

(Magma) I:=[1, 9, 82]; [n le 3 select I[n] else (9^(n-2)+1)*Self(n-1): n in [1..15]]; // Vincenzo Librandi, Nov 11 2012

Crossrefs

Sequence in context: A308481 A041146 A320991 * A174472 A039357 A048353

Adjacent sequences: A015494 A015495 A015496 * A015498 A015499 A015500

Keyword

nonn,easy

Author

Olivier Gérard

Status

approved