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Search: id:A108995
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| 1, 2, 9, 72, 890, 15456, 352807, 10093728, 349534881, 14270091790, 672991000968, 36076060520556, 2169580363847949, 144810568283675126, 10631141835083823945, 851921010801706760672, 74031550751810889131475
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OFFSET
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0,2
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COMMENT
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a(n) is divisible by (n+1). A108994 is the third diagonal of triangle A108990, in which the g.f. of row n, R_n(x), satisfies: [x^k] R_{n+1}(x) = [x^k] (1 + x*R_n(x))^(n+1) for k=0..n+1.
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FORMULA
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a(n) = A108990(n+2, n)*2/(n+2) for n>=0.
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PROGRAM
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(PARI) {a(n)=local(F=1); for(m=1, n+2, F=(1+x*F+x*O(x^n))^m); polcoeff(F, n)*2/(n+2)}
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CROSSREFS
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Cf. A108990, A108991, A108992, A108993, A108994, A108996.
Sequence in context: A133941 A038035 A133984 this_sequence A132843 A084873 A103996
Adjacent sequences: A108992 A108993 A108994 this_sequence A108996 A108997 A108998
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KEYWORD
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nonn
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AUTHOR
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Paul D. Hanna (pauldhanna(AT)juno.com), Jun 15 2005
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