A339286 Total number of interior vertices in the multigraphs of all unoriented series-parallel networks with n edges.

0, 1, 4, 17, 62, 255, 1026, 4363, 18656, 81446, 357708, 1584110, 7042396, 31429998, 140626375, 630640342, 2833200433, 12748771157, 57445747751, 259170739397, 1170566884224, 5292311737901, 23949417255984, 108470668735077, 491664303153769, 2230174016940385, 10122784007130716

Offset: 1

Author

Andrew Howroyd, Nov 30 2020

Keywords

• nonn

Comments

See A339285 for additional details.

Crossrefs

Cf. A339225, A339232, A339285.

Programs

PARI

\\ See A339285 for VertexWeighted.
seq(n)={subst(deriv(VertexWeighted(n,x,y)), y, 1)}

Formula

a(n) = Sum_{k=1..n-1} k*A339285(n,k).