OFFSET
0,2
COMMENTS
For comments see A326480.
MAPLE
# The function E2(n) is defined in A326480.
seq(subs(x=-1, E2(n)), n=0..22);
MATHEMATICA
T[n_, k_] := 2^n n! SeriesCoefficient[4 Exp[x z]/(Exp[z] + 1)^2, {z, 0, n}, {x, 0, k}]; Table[Sum[(-1)^k T[n, k], {k, 0, n}], {n, 0, 22}] (* Jean-François Alcover, Jul 23 2019 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Peter Luschny, Jul 12 2019
STATUS
approved