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 A014917 a(1)=1, a(n) = n*5^(n-1) + a(n-1). 3
 1, 11, 86, 586, 3711, 22461, 131836, 756836, 4272461, 23803711, 131225586, 717163086, 3890991211, 20980834961, 112533569336, 600814819336, 3194808959961, 16927719116211, 89406967163086, 470876693725586 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 Index entries for linear recurrences with constant coefficients, signature (11, -35, 25). FORMULA a(n) = (1/16)*(1 + 5^n*(4*n-1)). - Paolo P. Lava, Jan 13 2009 From Vincenzo Librandi, Oct 23 2012: (Start) a(n) = 10*a(n-1) - 25*a(n-2) + 1; a(1)=1, a(2)=11. G.f.: x/((1-x)*(1-5*x)^2). (End) a(n) = 11*a(n-1) - 35*a(n-2) + 25*a(n-3); a(1)=1, a(2)=11, a(3)=86. - Harvey P. Dale, May 06 2013 MATHEMATICA CoefficientList[Series[1/((1 - x)(1 - 5 x)^2), {x, 0, 40}], x] (* Vincenzo Librandi, Oct 23 2012 *) LinearRecurrence[{11, -35, 25}, {1, 11, 86}, 20] (* Harvey P. Dale, May 06 2013 *) PROG (MAGMA) I:=[1, 11]; [n le 2 select I[n] else 10*Self(n-1)-25*Self(n-2)+ 1: n in [1..30]]; // Vincenzo Librandi, Oct 23 2012 CROSSREFS Sequence in context: A320940 A012794 A302954 * A080962 A243879 A298253 Adjacent sequences:  A014914 A014915 A014916 * A014918 A014919 A014920 KEYWORD nonn,easy AUTHOR STATUS approved

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Last modified September 17 06:41 EDT 2019. Contains 327119 sequences. (Running on oeis4.)