A196191 G.f. satisfies A(x) = 1/Product_{n>=1} (1 - x^n/A(x^n)).

1, 1, 1, 1, 1, 2, 1, 3, 2, 3, 4, 4, 4, 6, 7, 7, 8, 10, 11, 12, 14, 17, 18, 20, 22, 26, 30, 31, 37, 39, 46, 49, 54, 61, 69, 74, 82, 91, 100, 114, 119, 136, 149, 159, 176, 193, 214, 227, 255, 276, 303, 324, 360, 394, 420, 462, 496, 548, 590, 638, 692, 749, 812, 874, 946, 1035, 1115, 1191, 1292, 1395, 1503

Offset: 0

Author

Paul D. Hanna, Sep 28 2011

Keywords

• nonn

Comments

The rate of growth of this sequence is surprisingly slow.

Examples

			G.f.: A(x) = 1 + x + x^2 + x^3 + x^4 + 2*x^5 + x^6 + 3*x^7 + 2*x^8 +...
where
A(x) = 1/((1 - x/A(x)) * (1 - x^2/A(x^2)) * (1 - x^3/A(x^3)) *...).
		

Links

• Paul D. Hanna, Table of n, a(n) for n = 0..512

Crossrefs

Cf. A050383, A196192.

Programs

PARI

{a(n)=local(A=1+x); for(i=1, n, A=1/prod(k=1, n, (1-x^k/subst(A, x, x^k+x*O(x^n))))); polcoeff(A, n)}