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Search: id:A098470
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| A098470 |
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Form array in which n-th row is obtained by expanding (1+x+x^2)^n and taking the 5th column from the center. |
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2
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| 1, 6, 28, 112, 414, 1452, 4917, 16236, 52624, 168168, 531531, 1665456, 5182008, 16031952, 49366674, 151419816, 462919401, 1411306358, 4292487562, 13029127584, 39478598170, 119439969220, 360881425710, 1089126806040
(list; graph; listen)
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OFFSET
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5,2
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COMMENT
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a(n) = A111808(n,n-5). - Reinhard Zumkeller (reinhard.zumkeller(AT)lhsystems.com), Aug 17 2005
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LINKS
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Eric Weisstein's World of Mathematics, Trinomial Coefficient
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FORMULA
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(n^2-25)*a(n)=n*(2*n-1)*a(n-1)+3*n*(n-1)*a(n-2). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Sep 18 2004
G.f.: 32*x^5/(sqrt((1+x)*(1-3*x))*(1-x-sqrt((1+x)*(1-3*x)))^5). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Sep 18 2004
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CROSSREFS
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Cf. A002426, A005717, A014531, A014532, A014533.
Sequence in context: A134416 A117999 A028379 this_sequence A055220 A027106 A089096
Adjacent sequences: A098467 A098468 A098469 this_sequence A098471 A098472 A098473
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KEYWORD
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nonn
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AUTHOR
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Eric Weisstein (eric(AT)weisstein.com), Sep 09, 2004
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