OFFSET
0,4
COMMENTS
First negative term is a(94).
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..200
MAPLE
A:= proc(n) option remember; if n=0 then 1 else unapply(convert(
series(exp(x*A(n-1)(sin(x)*x)), x, n+1), polynom), x) fi
end:
a:= n-> coeff(A(n)(x), x, n)*n!:
seq(a(n), n=0..30);
MATHEMATICA
A[n_] := A[n] = If[n == 0, 1, Normal[Series[Exp[x*A[n-1][Sin[x]*x]], {x, 0, n+1}]] /. x -> #]&; a[n_] := Coefficient[A[n][x], x, n]*n!; Table[a[n], {n, 0, 30}] (* Jean-François Alcover, Feb 14 2014, after Maple *)
CROSSREFS
KEYWORD
sign
AUTHOR
Alois P. Heinz, Aug 24 2008
STATUS
approved