A339039 - OEIS

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A339039

Number of unlabeled connected simple graphs with n edges rooted at one distinguished vertex.

1, 1, 2, 5, 13, 37, 114, 367, 1248, 4446, 16526, 63914, 256642, 1067388, 4590201, 20376849, 93240065, 439190047, 2126970482, 10579017047, 53983000003, 282345671127, 1512273916781, 8287870474339, 46438619162441, 265840311066579

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

LINKS

Table of n, a(n) for n=0..25.

FORMULA

G.f.: f(x)/g(x) where f(x) is the g.f. of A053419 and g(x) is the g.f. of A000664.

PROG

(PARI) \\ See A339063 for G.

seq(n)={my(A=O(x*x^n)); Vec(G(2*n, x+A, [1])/G(2*n, x+A, []))}

CROSSREFS

Cf. A000664, A002905, A053419, A126100, A303832, A339036, A339040, A339041, A339044, A339063.