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 A001341 E.g.f.: 6*exp(x)/(1-x)^4; (Formerly M4205 N1755) 3
 6, 30, 174, 1158, 8742, 74046, 696750, 7219974, 81762438, 1005151902, 13336264686, 189992451270, 2893180308774, 46904155833918, 806663460996462, 14669947577257926, 281298999630211590, 5672559830998316574, 120014233288249367598, 2658221288671765756422 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 REFERENCES N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS T. D. Noe, Table of n, a(n) for n = 0..100 E. Biondi, L. Divieti, G. Guardabassi, Counting paths, circuits, chains and cycles in graphs: A unified approach, Canad. J. Math. 22 1970 22-35. Philip Feinsilver and John McSorley, Zeons, Permanents, the Johnson Scheme, and Generalized Derangements, International Journal of Combinatorics, Volume 2011, Article ID 539030, 29 pages. FORMULA a(n) = ceiling( n!*(n^3 + 3*n^2 + 5*n + 2)*exp(1) ). - Mark van Hoeij, Nov 11 2009 G.f.: Q(0)*(1-x)^2/x^3 - 2/x + 1/x^2 - 1/x^3, where Q(k)= 1 + (2*k + 1)*x/( 1 - x - 2*x*(1-x)*(k+1)/(2*x*(k+1) + (1-x)/Q(k+1))); (continued fraction). - Sergei N. Gladkovskii, May 09 2013 MATHEMATICA nn = 20; Range[0, nn]! CoefficientList[Series[6*Exp[x]/(1 - x)^4, {x, 0, nn}], x] (* T. D. Noe, Jun 28 2012 *) PROG (PARI) x='x+O('x^66); Vec(serlaplace(6*exp(x)/(1-x)^4)) \\ Joerg Arndt, May 09 2013 CROSSREFS Sequence in context: A135490 A175925 A110706 * A089896 A057754 A001473 Adjacent sequences:  A001338 A001339 A001340 * A001342 A001343 A001344 KEYWORD nonn AUTHOR EXTENSIONS Error in definition corrected Jan 30 2008 More terms from N. J. A. Sloane, Jan 30 2008 STATUS approved

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Last modified June 5 11:52 EDT 2020. Contains 334840 sequences. (Running on oeis4.)