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 A130636 a(n) = n*a(n-3) + a(n-4) for n >= 4. 0
 0, 1, 0, 0, 4, 1, 0, 28, 12, 1, 280, 160, 24, 3641, 2520, 520, 58280, 46481, 11880, 1107840, 987900, 295961, 24384360, 23829540, 8090964, 609904961, 643952400, 242285568, 17085429872, 19284524561, 7912519440 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 LINKS FORMULA a(n) = n*a(n-3) + a(n-4) for n >= 4. - Jianing Song, Oct 10 2018 MATHEMATICA M[n_] := {{0, 0, n, 1}, {1, 0, 0, 0}, {0, 1, 0, 0}, {0, 0, 1, 0}}; v[0] = {0, 0, 0, 1}; v[n_] := v[n] = M[n].v[n - 1]; a = Table[v[n][[1]], {n, 0, 30}] PROG (PARI) a(n) = if(n<4, n==1, n*a(n-3) + a(n-4)) \\ Jianing Song, Oct 10 2018 CROSSREFS Sequence in context: A069018 A156811 A246609 * A299354 A117414 A085639 Adjacent sequences:  A130633 A130634 A130635 * A130637 A130638 A130639 KEYWORD nonn,easy AUTHOR Roger L. Bagula, Jun 19 2007 EXTENSIONS Edited, new name, and offset corrected by Jianing Song, Oct 10 2018 STATUS approved

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Last modified January 25 00:44 EST 2022. Contains 350565 sequences. (Running on oeis4.)