A090426 a(1) = 1, otherwise a(n) = floor(Pi^(n+1)/(Pi^2 + 1)).

0, 1, 2, 8, 28, 88, 277, 872, 2742, 8615, 27066, 85032, 267137, 839236, 2636539, 8282934, 26021606, 81749286, 256822957, 806833116, 2534740992, 7963123679, 25016890850, 78592880512, 246906816042, 775680639401, 2436872598274, 7655661052474, 24050968520828

Offset

0,3

Comments

a(n+1)/a(n) converges to Pi.

Links

Table of n, a(n) for n=0..28.

Formula

Let b(0)=0; b(1)=1; b(n+2)=(Pi-1/Pi)*b(n+1)+b(n). a(n)=floor(b(n)).

Mathematica

Join[{0, 1}, Table[Floor[Pi^(n + 1)/(Pi^2 + 1)], {n, 2, 28}]] (* Arkadiusz Wesolowski, Apr 20 2012 *)

Crossrefs

Cf. A090039, A090427, A093607, A093608.

Sequence in context: A087431 A176758 A178222 * A279193 A280279 A060995

Adjacent sequences: A090423 A090424 A090425 * A090427 A090428 A090429

Keyword

nonn

Author

Gary W. Adamson, Nov 30 2003

Extensions

Edited by Don Reble, Nov 14 2005

Name changed by Arkadiusz Wesolowski, Apr 20 2012

Status

approved