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A008390
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Crystal ball sequence for A_7 lattice.
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3
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1, 57, 869, 6637, 33111, 124223, 380731, 1004307, 2360501, 5064013, 10089705, 18912785, 33681595, 57426435, 94307855, 149907847, 231567369, 348773633, 513600589, 741206037, 1050388799, 1464209383
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Comment from T. D. Noe, Apr 29 2007: For the formula to produce this sequence, the three minus signs should be pluses and a 1 should be added: 143/210*n^7+143/60*n^6+451/60*n^5+77/6*n^4+937/60*n^3+707/60*n^2+363/70*n+1;
Comment from N. J. A. Sloane (njas(AT)research.att.com), May 04 2007: In that case I need to recheck both the formula and the values to see which is correct.
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LINKS
| 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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MAPLE
| 143/210*n^7-143/60*n^6+451/60*n^5+937/60*n^3+363/70*n-77/6*n^4-707/60*n^2;
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CROSSREFS
| Sequence in context: A084220 A060891 A098995 * A008922 A116181 A000505
Adjacent sequences: A008387 A008388 A008389 * A008391 A008392 A008393
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com) and J. H. Conway (conway(AT)math.princeton.edu)
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