OFFSET
4,2
FORMULA
a(n) = Stirling1(n,4) - (1/n) * Sum_{k=1..n-1} binomial(n,k) * Stirling1(n-k,4) * k * a(k).
MATHEMATICA
nmax = 23; CoefficientList[Series[Log[1 + Log[1 + x]^4/4!], {x, 0, nmax}], x] Range[0, nmax]! // Drop[#, 4] &
a[n_] := a[n] = StirlingS1[n, 4] - (1/n) Sum[Binomial[n, k] StirlingS1[n - k, 4] k a[k], {k, 1, n - 1}]; Table[a[n], {n, 4, 23}]
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Aug 08 2021
STATUS
approved