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Search: id:A129452
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| A129452 |
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Generating function in rational polynomials from Billey-Warrington paper for q=3:p(x, q) = (-1 + q^2*x^2 + q^3*x^3)/((1 + q*x + q^2*x^2)*(-1 + x + q*x + q^2*x^2 + q^2*x^3 - q^4*x^4)). |
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+0 1
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| 1, 1, 4, 61, 208, 1093, 7198, 35560, 193450, 1089772, 5837140, 31840051, 174564403, 949080799, 5176371973, 28253599486, 154003756249, 839880083245, 4580937825271, 24980164298164, 136230227328730, 742951002036193
(list; graph; listen)
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OFFSET
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1,3
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REFERENCES
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Sara Billey, Gregory Warrington,Kazhdan-Lusztig Polynomials for 321-hexagon-avoiding permutations, J. of Algebraic Combinatorics, page 132; http://www.math.washington.edu/~billey/
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FORMULA
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a(n) =Expansion of((-1+q^2*x^2+q^3*x^3)/((1+q*x+q^2*x^2)*(-1+x+q*x+q^2*x^2+q^2*x^3-q^4*x^4))) for q=3
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MATHEMATICA
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p[x_, q_] = (-1 + q^2*x^2 + q^3*x^3)/((1 + q*x + q^2*x^2)*(-1 + x + q*x + q^2*x^2 + q^2*x^3 - q^4*x^4)); Table[ SeriesCoefficient[Series[p[x, 3], {x, 0, 30}], n], {n, 0, 30}]
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CROSSREFS
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Adjacent sequences: A129449 A129450 A129451 this_sequence A129453 A129454 A129455
Sequence in context: A132627 A136385 A071582 this_sequence A131014 A118005 A132064
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KEYWORD
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nonn,uned
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AUTHOR
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Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Jun 08 2007
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