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A035754
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Coordination sequence for C_17 lattice.
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1
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1, 578, 56066, 2220098, 48663554, 693230658, 7094825730, 55871829570, 355761664002, 1900906442306, 8769652761346, 35721495233602, 130777539341314, 436553052633154, 1344455730686722, 3857284100508226, 10393582407041026, 26482855453375042, 64180094992435970
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OFFSET
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0,2
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LINKS
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J. H. Conway and N. J. A. Sloane, Low-Dimensional Lattices VII: Coordination Sequences, Proc. Royal Soc. London, A453 (1997), 2369-2389 (pdf).
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FORMULA
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G.f.: Sum_{n>=0} a(n)x^(2n) = ( ((1+x)/(1-x))^17 +((1-x)/(1+x))^17 )/2. - Michael Somos, Aug 03 2006
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PROG
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(PARI) {a(n)=if(n<0, 0, n*=2; polcoeff( ((1+x)/(1-x)+x*O(x^n))^17, n))} /* Michael Somos, Aug 03 2006 */
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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Joan Serra-Sagrista (jserra(AT)ccd.uab.es)
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EXTENSIONS
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STATUS
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approved
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