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A117443
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E.g.f. exp(x)/(cos(x)+sin(x)).
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1
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1, 0, 2, -4, 28, -160, 1272, -11184, 114448, -1309440, 16680992, -233587264, 3569157568, -59075960320, 1053056675712, -20111857791744, 409715696197888, -8868323731660800, 203247024658514432, -4916860703228314624, 125206830774036241408, -3347784042587048058880
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| Row sums of number triangle A117442. Binomial transform of alternating sign Springer numbers (-1)^n*A001586(n).
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FORMULA
| E.g.f.: A(x)=exp(x)/(cos(x)+sin(x))=1/Q(0); Q(k)=1-(x^2)/((4*k+1)*(2*k+1)+2*x*(4*k+1)*(2*k+1)/(4*k+3-2*x-x*(4*k+3)/(x-(4*k+4)/Q(k+1)))) ; (continued fraction). - Sergei N. Gladkovskii, Nov 28 2011
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CROSSREFS
| Sequence in context: A110881 A156449 A192374 * A095858 A062792 A102692
Adjacent sequences: A117440 A117441 A117442 * A117444 A117445 A117446
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KEYWORD
| easy,sign
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Mar 16 2006
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