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 A219757 Expansion of x^4*(2-7*x+6*x^2+x^3-x^4)/((1-x)*(1-2*x)^4*(1-3*x+x^2)). 1
 0, 0, 0, 0, 2, 17, 90, 383, 1436, 4958, 16159, 50480, 152690, 450343, 1301764, 3701990, 10387887, 28827688, 79265482, 216271927, 586261980, 1580524894, 4241295935, 11336890720, 30202962402, 80239307847, 212664541940, 562513804438, 1485379408591, 3916726647768 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..1000 M. H. Albert, M. D. Atkinson and Robert Brignall, The enumeration of three pattern classes, arXiv:1206.3183 (2012), p. 25. Index entries for linear recurrences with constant coefficients, signature (12,-60,161,-248,216,-96,16). FORMULA G.f.: x^4*(2-7*x+6*x^2+x^3-x^4)/((1-x)*(1-2*x)^4*(1-3*x+x^2)). MATHEMATICA CoefficientList[Series[x^4(2-7x+6x^2+x^3-x^4)/((1-x)(1-2x)^4(1-3x+x^2)), {x, 0, 40}], x] (* Harvey P. Dale, Nov 29 2012 *) PROG (Maxima) makelist(coeff(taylor(x^4*(2-7*x+6*x^2+x^3-x^4)/((1-x)*(1-2*x)^4*(1-3*x+x^2)), x, 0, n), x, n), n, 0, 29); [Bruno Berselli, Nov 29 2012] (MAGMA) I:=[0, 0, 0, 0, 2, 17, 90, 383, 1436, 4958]; [n le 10 select I[n] else 12*Self(n-1) - 60*Self(n-2) + 161*Self(n-3) - 248*Self(n-4) + 216*Self(n-5) - 96*Self(n-6) + 16*Self(n-7): n in [1..30]]; // Vincenzo Librandi, Dec 14 2012 CROSSREFS Cf. A219751-A219759, A219837. Sequence in context: A181546 A320644 A081744 * A297727 A002645 A100268 Adjacent sequences:  A219754 A219755 A219756 * A219758 A219759 A219760 KEYWORD nonn,easy AUTHOR N. J. A. Sloane, Nov 28 2012 STATUS approved

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Last modified June 19 04:44 EDT 2019. Contains 324217 sequences. (Running on oeis4.)