login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A191636 a(n) = floor((-1 + 4^n)/(-1 + 2*n)). 3
3, 5, 12, 36, 113, 372, 1260, 4369, 15420, 55188, 199728, 729444, 2684354, 9942053, 37025580, 138547332, 520602096, 1963413621, 7429132620, 28192605840, 107269427100, 409120605684, 1563749870614, 5988829291716, 22977549119237, 88305875046480, 339894311499660 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MATHEMATICA

f[n_] := Floor[(-1+4^n)/(-1+2 n)]

Table[f[n], {n, 1, 40}]     (* A191636 *)

PROG

(MAGMA) [Floor((-1+4^n)/(-1+2*n)): n in [1..30] ]; // Vincenzo Librandi, Sep 10 2011

(Maxima) A191636(n):=floor((-1+4^n)/(-1+2*n))$ makelist(A191636(n), n, 1, 30); /* Martin Ettl, Oct 25 2012 */

CROSSREFS

Cf. A191637.

Sequence in context: A323270 A087610 A243013 * A267337 A308544 A307142

Adjacent sequences:  A191633 A191634 A191635 * A191637 A191638 A191639

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jun 09 2011

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 24 03:22 EST 2020. Contains 332195 sequences. (Running on oeis4.)