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A373520
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Expansion of e.g.f. exp(x/(1 - x^4)^(1/2)).
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3
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1, 1, 1, 1, 1, 61, 361, 1261, 3361, 143641, 1829521, 12501721, 59922721, 2173048021, 44315751481, 478799701381, 3492321094081, 116722067432881, 3290135175240481, 50242015215929521, 508061488330088641, 16418736123292904941, 585427887134915295241
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OFFSET
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0,6
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LINKS
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FORMULA
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a(n) = n! * Sum_{k=0..floor(n/4)} binomial(n/2-k-1,k)/(n-4*k)!.
a(n) == 1 mod 60.
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PROG
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(PARI) a(n) = n!*sum(k=0, n\4, binomial(n/2-k-1, k)/(n-4*k)!);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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