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A010025
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Crystal ball sequence for squashed {D_5}^* lattice, perhaps the smallest example of a "non-superficial" lattice.
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1
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1, 13, 85, 377, 1239, 3291, 7503, 15275, 28517, 49729, 82081, 129493, 196715, 289407, 414219, 578871, 792233, 1064405, 1406797, 1832209, 2354911, 2990723, 3757095, 4673187, 5759949, 7040201, 8538713
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OFFSET
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0,2
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LINKS
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T. D. Noe, Table of n, a(n) for n=0..1000
Index entries for crystal ball sequences
J. H. Conway and N. J. A. Sloane, Low-Dimensional Lattices VII: Coordination Sequences, Proc. Royal Soc. London, A453 (1997), 2369-2389 (Abstract, pdf, ps).
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FORMULA
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From Gopinath A. R., Feb 14 2012, (Start)
G.f.: (x^5+7*x^4+42*x^3+22*x^2+7*x+1)/(x^6-6*x^5+15*x^4-20*x^3+15*x^2-6*x+1).
E.g.f.: 1/12*(8*x^5+95*x^4+320*x^3+360*x^2+144*x+12)*exp(x). (End)
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MAPLE
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2/3*n^5+5/4*n^4+5/2*n^3+15/4*n^2+23/6*n+1;
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CROSSREFS
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Sequence in context: A163688 A225129 A222491 * A001848 A055843 A003764
Adjacent sequences: A010022 A010023 A010024 * A010026 A010027 A010028
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane.
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STATUS
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approved
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