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A331978
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E.g.f.: -log(2 - cosh(x)) (even powers only).
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2
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0, 1, 4, 46, 1114, 46246, 2933074, 263817646, 31943268634, 5009616448246, 987840438629794, 239217148602642046, 69790939492563608554, 24143849395162438623046, 9772368696995766705116914, 4575221153658910691872135246, 2453303387149157947685779986874
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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(0) = 0; a(n) = A094088(n) - (1/n) * Sum_{k=1..n-1} binomial(2*n,2*k) * A094088(n-k) * k * a(k).
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MAPLE
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ptan := proc(n) option remember;
if irem(n, 2) = 0 then 0 else
add(`if`(k=0, 1, binomial(n, k)*ptan(n - k)), k = 0..n-1, 2) fi end:
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MATHEMATICA
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nmax = 16; Table[(CoefficientList[Series[-Log[2 - Cosh[x]], {x, 0, 2 nmax}], x] Range[0, 2 nmax]!)[[n]], {n, 1, 2 nmax + 1, 2}]
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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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