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 A174836 a(n) = 1 + ((6*n-1)*2^n + (-1)^n)/3. 0
 1, 4, 16, 46, 124, 310, 748, 1750, 4012, 9046, 20140, 44374, 96940, 210262, 453292, 972118, 2075308, 4412758, 9349804, 19748182, 41593516, 87381334, 183151276, 383079766, 799713964, 1666536790, 3467291308, 7203018070, 14942907052, 30959555926, 64066595500, 132428158294 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Index entries for linear recurrences with constant coefficients, signature (4, -3, -4, 4). FORMULA G.f.: 1/(1-x) + 1/(3*(1+x)) - 1/(3*(1-2*x)) + 8*x/(1-2*x)^2. [Richard Choulet, Apr 04 2010] a(n) = 3*A113861(n+1) + 1. - Michel Marcus, Feb 05 2019 PROG (PARI) a(n) = 1 + ((6*n-1)*2^n+(-1)^n)/3; \\ Michel Marcus, Feb 05 2019 CROSSREFS Cf. A113861. Sequence in context: A007315 A055342 A213292 * A244252 A308592 A050616 Adjacent sequences:  A174833 A174834 A174835 * A174837 A174838 A174839 KEYWORD nonn,easy AUTHOR Fernando J. Ballesteros (fernando.ballesteros(AT)uv.es), Mar 30 2010 EXTENSIONS More terms from Michel Marcus, Feb 05 2019 STATUS approved

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Last modified June 30 06:00 EDT 2022. Contains 354914 sequences. (Running on oeis4.)