A053454 - OEIS

%I #12 Jan 28 2022 21:52:28

%S 1,1,4,12,53,237,1306,7537,47913,322253,2297874,17191216,134505656,

%T 1095715055,9267223594,81162609328,734511656413,6856030049629,

%U 65899370570285,651338242941020,6611459646337423,68842439737228261

%N Number of weakly connected digraphs with n arcs.

%H Andrew Howroyd, <a href="/A053454/b053454.txt">Table of n, a(n) for n = 0..50</a>

%F Inverse Euler transform of A053418. - _Max Alekseyev_, Jan 22 2010

%o (PARI) \\ See A054733 for G, InvEulerMTS.

%o seq(n)=Vec(subst(Pol(InvEulerMTS(sum(i=0, n, G(i, y+O(y^n))*x^i, O(x*x^n)))), x, 1)) \\ _Andrew Howroyd_, Jan 28 2022

%Y Column sums of A054733.

%Y Row sums of A350789.

%Y Cf. A003085, A053418, A350752.

%K nonn

%O 0,3

%A _Vladeta Jovovic_, Jan 12 2000

%E Extended by _Max Alekseyev_, Jan 22 2010

%E a(0)=1 prepended by _Andrew Howroyd_, Jan 28 2022