A191639 a(n) = floor((1 + 4^n)/(1 + 3*n)).

1, 2, 6, 19, 64, 215, 744, 2621, 9362, 33825, 123361, 453438, 1677721, 6242685, 23342213, 87652393, 330382099, 1249445031, 4739274257, 18024780783, 68719476736, 262569940961, 1005267773966, 3855821598776, 14814472458455, 57007590219879, 219687786700999

Offset

1,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Mathematica

f[n_] := Floor[(1+4^n)/(1+3 n)]
Table[f[n], {n, 1, 40}]     (* A191639 *)

Prog

(Magma) [Floor((1+4^n)/(1+3*n)): n in [1..30] ]; // Vincenzo Librandi, Sep 10 2011
(Maxima) A191639(n):=floor((1+4^n)/(1+3*n))$ makelist(A191639(n), n, 1, 30); /* Martin Ettl, Oct 25 2012 */

Crossrefs

Cf. A191638.

Sequence in context: A148467 A148468 A148469 * A329802 A151283 A176950

Adjacent sequences: A191636 A191637 A191638 * A191640 A191641 A191642

Keyword

nonn

Author

Clark Kimberling, Jun 09 2011

Status

approved