A141628 E.g.f. satisfies: A(x) = exp(x*A(tan(x))).

1, 1, 3, 16, 133, 1496, 21343, 371064, 7633641, 181891072, 4937228411, 150669126400, 5114378969965, 191400122127488, 7838565428874391, 349073700821172736, 16811407320683479633, 871413633401197096960

Offset

0,3

Links

Alois P. Heinz, Table of n, a(n) for n = 0..100

Maple

A:= proc(n) option remember; if n=0 then 1 else unapply (convert (series (exp (x*A(n-1)(tan(x))), x, n+1), polynom), x) fi end: a:= n-> coeff (A(n)(x), x, n)*n!: seq (a(n), n=0..19);

Mathematica

A[n_] := A[n] = If[n == 0, 1, Normal[Series[Exp[x*A[n-1][Tan[x]]], {x, 0, n+1}]] /. x -> #]&; a[n_] := Coefficient[A[n][x], x, n]*n!; Table[a[n], {n, 0, 19}] (* Jean-François Alcover, Feb 14 2014, after Maple *)

Crossrefs

Sequence in context: A023998 A241464 A341852 * A048802 A213357 A119392

Adjacent sequences: A141625 A141626 A141627 * A141629 A141630 A141631

Keyword

nonn

Author

Alois P. Heinz, Aug 24 2008

Status

approved