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 A190441 a(n) = 4*a(n-1) + 39*a(n-2), with a(0)=0, a(1)=1. 2
 0, 1, 4, 55, 376, 3649, 29260, 259351, 2178544, 18828865, 160278676, 1375440439, 11752630120, 100652697601, 860963365084, 7369308666775, 63054805905376, 539622261625729, 4617626476812580, 39515774110653751, 338150529038305624, 2893717306468718785 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Bruno Berselli, Table of n, a(n) for n = 0..300 FORMULA G.f.: x/(1-4*x-39*x^2). a(n) = ((2+sqrt(43))^n - (2-sqrt(43))^n)/(2*sqrt(43)). MATHEMATICA a = {0, 1}; Do[AppendTo[a, 4 a[[-1]] + 39 a[[-2]]], {20}]; a (* Bruno Berselli, Dec 26 2012 *) CoefficientList[Series[x / (1 - 4 x - 39 x^2), {x, 0, 25}], x] (* Vincenzo Librandi, Aug 19 2013 *) PROG (Maxima) a[0]:0\$ a[1]:1\$ a[n]:=4*a[n-1]+39*a[n-2]\$ makelist(a[n], n, 0, 17); (MAGMA)  [n le 2 select n-1 else 4*Self(n-1)+39*Self(n-2): n in [1..22]]; (PARI) x='x+O('x^30); concat([0], Vec(x/(1-4*x-39*x^2))) \\ G. C. Greubel, Dec 30 2017 CROSSREFS Cf. A015611, A190943 (with similar closed forms). Sequence in context: A217124 A064439 A133218 * A151576 A204107 A285366 Adjacent sequences:  A190438 A190439 A190440 * A190442 A190443 A190444 KEYWORD nonn,easy AUTHOR Bruno Berselli, May 25 2011 STATUS approved

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Last modified September 16 06:38 EDT 2019. Contains 327090 sequences. (Running on oeis4.)