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 A162256 a(n) = (2*n^3 + 5*n^2 - 3*n)/2. 2
 2, 15, 45, 98, 180, 297, 455, 660, 918, 1235, 1617, 2070, 2600, 3213, 3915, 4712, 5610, 6615, 7733, 8970, 10332, 11825, 13455, 15228, 17150, 19227, 21465, 23870, 26448, 29205, 32147, 35280, 38610, 42143, 45885, 49842, 54020, 58425, 63063, 67940 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Row sums from A154680. LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1). FORMULA From Vincenzo Librandi, Mar 04 2012: (Start) G.f.: x*(2 + 7*x - 3*x^2)/(1-x)^4. a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). (End) MATHEMATICA LinearRecurrence[{4, -6, 4, -1}, {2, 15, 45, 98}, 50] (* or *) CoefficientList[Series[(2+7*x-3*x^2)/(1-x)^4, {x, 0, 39}], x] (* Vincenzo Librandi, Mar 04 2012 *) PROG (PARI) n*(5*n-3)/2+n^3 \\ Charles R Greathouse IV, Jan 11 2012 CROSSREFS Sequence in context: A300393 A152015 A318914 * A229013 A256328 A041719 Adjacent sequences:  A162253 A162254 A162255 * A162257 A162258 A162259 KEYWORD nonn,easy AUTHOR Vincenzo Librandi, Jun 29 2009 STATUS approved

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Last modified January 22 05:11 EST 2019. Contains 319353 sequences. (Running on oeis4.)