A099696 - OEIS

%I #12 Jan 12 2021 19:51:53

%S 1,1,4,25,244,3380,62133,1440382,40673705,1364815169,53415511305,

%T 2402797049419,122751622204827,7051227704802797,451598420376965588,

%U 32013004761567761223,2495936511077175475140,212840593118800653411004,19753575434503894710824531

%N Consider the family of multigraphs enriched by the species of involutions. Sequence gives number of those multigraphs with n labeled edges.

%D G. Paquin, Dénombrement de multigraphes enrichis, Mémoire, Math. Dept., Univ. Québec à Montréal, 2004.

%H Andrew Howroyd, <a href="/A099696/b099696.txt">Table of n, a(n) for n = 0..100</a>

%H G. Paquin, <a href="/A038205/a038205.pdf">Dénombrement de multigraphes enrichis</a>, Mémoire, Math. Dept., Univ. Québec à Montréal, 2004. [Cached copy, with permission]

%F E.g.f.: B(R(x)) where B(x) is the e.g.f. of A014500 and 1 + R(x) is the e.g.f. of A000085. - _Andrew Howroyd_, Jan 12 2021

%o (PARI) \\ R(n) is A000085 as e.g.f.; EnrichedGnSeq defined in A098620.

%o R(n)={exp(x+x^2/2 + O(x*x^n))}

%o EnrichedGnSeq(R(20)) \\ _Andrew Howroyd_, Jan 12 2021

%Y Cf. A000085, A014500, A098620, A099697, A099698, A099699.

%K nonn

%O 0,3

%A _N. J. A. Sloane_, Oct 26 2004

%E Terms a(11) and beyond from _Andrew Howroyd_, Jan 12 2021