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 A189375 Expansion of 1/((1-x)^5*(x^3+x^2+x+1)^3). 4
 1, 2, 3, 4, 8, 12, 16, 20, 30, 40, 50, 60, 80, 100, 120, 140, 175, 210, 245, 280, 336, 392, 448, 504, 588, 672, 756, 840, 960, 1080, 1200, 1320, 1485, 1650, 1815, 1980, 2200, 2420, 2640, 2860, 3146, 3432, 3718, 4004, 4368 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS The Gi1 triangle sums of A139600 lead to the sequence given above, see the formulas. For the definitions of the Gi1 and other triangle sums see A180662. LINKS Index entries for linear recurrences with constant coefficients, signature (2, -1, 0, 3, -6, 3, 0, -3, 6, -3, 0, 1, -2, 1). FORMULA a(n) = sum(A056594(n-k)*A115269(k), k=0..n). Gi1(n) = A189375(n-4) - A189375(n-5) - A189375(n-8) + 2*A189375(n-9) with A189375(n)=0 for n <= -1. a(n) = (2*n^4+56*n^3+538*n^2+2044*n+2469+3*((2*n^2+28*n+89)*(-1)^n+(4*(-1)^((2*n-1+(-1)^n)/4)*(n^2+16*n+57-(n^2+12*n+29)*(-1)^n))))/3072. - Luce ETIENNE, Jun 25 2015 MAPLE a:= n-> coeff(series(1/((1-x)^5*(x^3+x^2+x+1)^3), x, n+1), x, n): seq(a(n), n=0..50); MATHEMATICA CoefficientList[Series[1/((1-x)^5(x^3+x^2+x+1)^3), {x, 0, 50}], x] (* or *) LinearRecurrence[{2, -1, 0, 3, -6, 3, 0, -3, 6, -3, 0, 1, -2, 1}, {1, 2, 3, 4, 8, 12, 16, 20, 30, 40, 50, 60, 80, 100}, 50] (* Harvey P. Dale, Dec 05 2014 *) CROSSREFS Cf. A139600, A189374, A189376. Sequence in context: A032939 A030073 A115271 * A262975 A062923 A133464 Adjacent sequences:  A189372 A189373 A189374 * A189376 A189377 A189378 KEYWORD easy,nonn AUTHOR Johannes W. Meijer, Apr 29 2011 STATUS approved

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Last modified June 16 21:18 EDT 2019. Contains 324155 sequences. (Running on oeis4.)