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 A180226 a(n) = 4*a(n-1) + 10*a(n-2), with a(1)=0 and a(2)=1. 11
 0, 1, 4, 26, 144, 836, 4784, 27496, 157824, 906256, 5203264, 29875616, 171535104, 984896576, 5654937344, 32468715136, 186424233984, 1070384087296, 6145778689024, 35286955629056, 202605609406464, 1163291993916416, 6679224069730304, 38349816218085376 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Nathaniel Johnston, Table of n, a(n) for n = 1..500 Index entries for linear recurrences with constant coefficients, signature (4, 10). FORMULA a(n) = ((2+sqrt(14))^(n-1) - (2-sqrt(14))^(n-1))/(2*sqrt(14)). - Rolf Pleisch, May 14 2011 G.f.: x^2/(1-4*x-10*x^2). MATHEMATICA Join[{a=0, b=1}, Table[c=4*b+10*a; a=b; b=c, {n, 100}]] LinearRecurrence[{4, 10}, {0, 1}, 30] (* G. C. Greubel, Jan 16 2018 *) PROG (PARI) x='x+O('x^30); concat([0], Vec(x^2/(1-4*x-10*x^2))) \\ G. C. Greubel, Jan 16 2018 (MAGMA) I:=[0, 1]; [n le 2 select I[n] else 4*Self(n-1) + 10*Self(n-2): n in [1..30]]; // G. C. Greubel, Jan 16 2018 CROSSREFS Cf. A001076, A006190, A007482, A015520, A015521, A015523, A015524, A015525, A015528, A015529, A015530, A015531, A015532, A015533, A015534, A015443, A015447, A030195, A053404, A057087, A083858, A085939, A090017, A091914, A099012, A180222. Sequence in context: A197964 A100236 A229278 * A325587 A223627 A144068 Adjacent sequences:  A180223 A180224 A180225 * A180227 A180228 A180229 KEYWORD nonn,easy AUTHOR Vladimir Joseph Stephan Orlovsky, Jan 16 2011 STATUS approved

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Last modified December 6 04:14 EST 2019. Contains 329784 sequences. (Running on oeis4.)