A199104 G.f. satisfies: A(x) = exp( Sum_{n>=1} A(x^n)/(1-x)^n * x^n/n ).

1, 1, 3, 9, 28, 88, 284, 931, 3109, 10532, 36162, 125546, 440201, 1556519, 5544715, 19879791, 71685522, 259809731, 945913555, 3457947627, 12687782600, 46709518473, 172484216742, 638712762962, 2371241532557, 8824154454401, 32909438791706, 122984173008460

Offset

0,3

Links

Table of n, a(n) for n=0..27.

Example

G.f.: A(x) = 1 + x + 3*x^2 + 9*x^3 + 28*x^4 + 88*x^5 + 284*x^6 + 931*x^7 +...
where
log(A(x)) = A(x)/(1-x)*x + A(x^2)/(1-x)^2*x^2/2 + A(x^3)/(1-x)^3*x^3/3 +...

Prog

(PARI) {a(n)=local(A=1+x); for(i=1, n, A=exp(sum(m=1, n, (1-x)^-m*x^m/m*subst(A, x, x^m+x*O(x^n))))); polcoeff(A, n)}

Crossrefs

Cf. A199103.

Sequence in context: A170953 A358092 A333504 * A049220 A094790 A007822

Adjacent sequences: A199101 A199102 A199103 * A199105 A199106 A199107

Keyword

nonn

Author

Paul D. Hanna, Nov 03 2011

Status

approved