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A187650
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Alternated cumulative sums of the (signless) central Stirling numbers of the first kind (A187646).
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0
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1, 0, 11, 214, 6555, 262770, 13076765, 777866388, 53853263165, 4254252038764, 377667803463431, 37222867283396314, 4033161189724173207, 476511397553009371918, 60969023704806106263737, 8398605422371512041566888
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OFFSET
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0,3
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LINKS
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FORMULA
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a(n) = sum((-1)^(n-k)s(2k,k)),k=0..n)
a(n) ~ 2^(3*n-1) * c^(2*n) * n^(n - 1/2) / (sqrt(Pi*(c-1)) * (2*c-1)^n * exp(n)), where c = -LambertW(-1,-exp(-1/2)/2) = 1.7564312086261696769827376166... - Vaclav Kotesovec, Jul 05 2021
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MAPLE
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seq(sum((-1)^(n-k)*abs(combinat[stirling1](2*k, k)), k=0..n), n=0..12);
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MATHEMATICA
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Table[Sum[(-1)^(n-k)Abs[StirlingS1[2k, k]], {k, 0, n}], {n, 0, 15}]
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PROG
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(Maxima) makelist(sum((-1)^(n-k)*abs(stirling1(2*k, k)), k, 0, n), n, 0, 12);
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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