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 A028289 Expansion of (1+x^2+x^3+x^5)/((1-x)(1-x^3)(1-x^4)(1-x^6)). 4
 1, 1, 2, 4, 5, 7, 11, 13, 17, 23, 27, 33, 42, 48, 57, 69, 78, 90, 106, 118, 134, 154, 170, 190, 215, 235, 260, 290, 315, 345, 381, 411, 447, 489, 525, 567, 616, 658, 707, 763, 812, 868, 932, 988, 1052, 1124, 1188 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS C. Ahmed, P. Martin, V. Mazorchuk, On the number of principal ideals in d-tonal partition monoids, arXiv preprint arXiv:1503.06718 [math.CO], 2015. B. N. Cyvin et al., Enumeration of conjugated hydrocarbons: Hollow hexagons revisited, Structural Chem., 6 (1995), 85-88, equations (6) and (22). W. C. Huffman, The biweight enumerator of self-orthogonal binary codes, Discr. Math. Vol. 26 1979, pp. 129-143. Index entries for linear recurrences with constant coefficients, signature (1,1,1,-2,-2,1,1,1,-1). FORMULA G.f.: 1 / ( (1+x)*(1+x+x^2)^2*(x-1)^4 ). - R. J. Mathar, Mar 22 2011 MAPLE A117373 := proc(n) op(1+(n mod 6), [1, -2, -3, -1, 2, 3]) ; end proc: A076118 := proc(n) coeftayl( x*(1-x)/(1-x+x^2)^2, x=0, n) ; end proc: A028289 := proc(n) 1/108*n^3 +1/8*n^2 +55/108*n +29/48 +1/16*(-1)^n -2*(-1)^n*A117373(n+2)/27 +(-1)^n*A076118(n+1)/9; end proc: seq(A028289(n), n=0..20) ; # R. J. Mathar, Mar 22 2011 MATHEMATICA CoefficientList[Series[(1+x^2+x^3+x^5)/((1-x)(1-x^3)(1-x^4) (1-x^6)), {x, 0, 50}], x]  (* Harvey P. Dale, Apr 20 2011 *) PROG (PARI) Vec((1+x^2+x^3+x^5)/((1-x)*(1-x^3)*(1-x^4)*(1-x^6))+O(x^99)) \\ Charles R Greathouse IV, Sep 26 2012 CROSSREFS Sequence in context: A033160 A110924 A192590 * A307872 A239510 A039673 Adjacent sequences:  A028286 A028287 A028288 * A028290 A028291 A028292 KEYWORD nonn,easy AUTHOR STATUS approved

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Last modified October 14 07:31 EDT 2019. Contains 327995 sequences. (Running on oeis4.)