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A191638 a(n) = floor((-1 + 4^n)/(-1 + 3*n)). 2
1, 3, 7, 23, 73, 240, 819, 2849, 10082, 36157, 131071, 479349, 1766022, 6547206, 24403223, 91382282, 343597383, 1296593900, 4908534052, 18635790301, 70936234050, 270649016067, 1034834473200, 3964436291699, 15214863605981, 58488306848967, 225179981368524 (list; graph; refs; listen; history; text; internal format)
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}]     (* A191638 *)

PROG

(MAGMA) [Floor((-1+4^n)/(-1+3*n)): n in [1..30] ]; // Vincenzo Librandi, Sep 10 2011

(Maxima) A191638(n):=floor((-1+4^n)/(-1+3*n))$ makelist(A191638(n), n, 1, 30); /* Martin Ettl, Oct 25 2012 */

CROSSREFS

Cf. A191639.

Sequence in context: A133435 A079061 A228724 * A148704 A283109 A057184

Adjacent sequences:  A191635 A191636 A191637 * A191639 A191640 A191641

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jun 09 2011

STATUS

approved

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Last modified February 27 22:50 EST 2020. Contains 332319 sequences. (Running on oeis4.)