OFFSET
0,3
COMMENTS
Inverse boustrophedon transform of Fubini numbers.
FORMULA
a(n) ~ n! * (1 - sin(log(2))) / (2 * cos(log(2)) * log(2)^(n+1)). - Vaclav Kotesovec, Aug 23 2021
MATHEMATICA
nmax = 21; CoefficientList[Series[(Sec[x] - Tan[x])/(2 - Exp[x]), {x, 0, nmax}], x] Range[0, nmax]!
t[n_, 0] := Sum[StirlingS2[n, k] k!, {k, 0, n}]; t[n_, k_] := t[n, k] = t[n, k - 1] - t[n - 1, n - k]; a[n_] := t[n, n]; Table[a[n], {n, 0, 21}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Aug 15 2021
STATUS
approved