login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A133511
a(n) = 3 A113405(n)- A113405(n+1).
0
0, 0, -1, 1, 2, 5, 7, 14, 27, 57, 114, 229, 455, 910, 1819, 3641, 7282, 14565, 29127, 58254, 116507, 233017, 466034, 932069, 1864135, 3728270, 7456539, 14913081, 29826162, 59652325, 119304647, 238609294, 477218587, 954437177, 1908874354, 3817748709, 7635497415
OFFSET
0,5
FORMULA
2a(n)-a(n+1)=A133513(n).
A113405(n)-a(n)=A131531(n).
O.g.f.: x^2(3x-1)/((1-2x)(1+x)(1-x+x^2)). - R. J. Mathar, Jul 22 2008
a(n+2)=4*(2^n-(-1)^n)/9+A117373(n+2)/3. [From R. J. Mathar, Jul 20 2009]
CROSSREFS
Sequence in context: A228208 A338231 A286573 * A257025 A076720 A245921
KEYWORD
sign
AUTHOR
Paul Curtz, Nov 30 2007
EXTENSIONS
Edited and extended by R. J. Mathar, Jul 22 2008
STATUS
approved