A231934 G.f. A(x) satisfies: A'(x) = A(B(x)) where B'(x) = A(x) with B(0)=0 and A(0)=1.

1, 1, 1, 2, 6, 27, 163, 1271, 12354, 145801, 2047083, 33642256, 638588460, 13845027215, 339607971556, 9347964267192, 286688210033698, 9734737020358855, 363942977852123850, 14906164891970353970, 665835978084064725837, 32304867226779146102085, 1696127595521806495181023

Offset

0,4

Links

Table of n, a(n) for n=0..22.

Example

E.g.f.: A(x) = 1 + x + x^2/2! + 2*x^3/3! + 6*x^4/4! + 27*x^5/5! + 163*x^6/6! +...
Related expansions.
A'(x) = A(B(x)) = 1 + x + 2*x^2/2! + 6*x^3/3! + 27*x^4/4! + 163*x^5/5! +...
where B'(x) = A(x):
B(x) = x + x^2/2! + x^3/3! + 2*x^4/4! + 6*x^5/5! + 27*x^6/6! + 163*x^7/7! +...

Prog

(PARI) {a(n) = my(A=1+x); for(i=1, n, A = 1 + intformal(subst(A, x, intformal(A +x*O(x^n))))); n!*polcoeff(A, n)}
for(n=0, 25, print1(a(n), ", "))

Crossrefs

Sequence in context: A122938 A352139 A234568 * A291979 A070076 A227222

Adjacent sequences: A231931 A231932 A231933 * A231935 A231936 A231937

Keyword

nonn

Author

Paul D. Hanna, Nov 15 2013

Status

approved