cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A215865 Number of simple labeled graphs on n+5 nodes with exactly n connected components that are trees or cycles.

Original entry on oeis.org

0, 1356, 15029, 90734, 394506, 1381695, 4138827, 11002068, 26603148, 59546487, 124984860, 248436188, 471271892, 858408642, 1508851218, 2569865520, 4255708464, 6872006526, 10847057991, 16771536474, 25448295950, 37954221305, 55716334245, 80604653220
Offset: 0

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Author

Alois P. Heinz, Aug 25 2012

Keywords

Crossrefs

A diagonal of A215861.

Programs

  • Maple
    a:= n-> binomial(n+5,6)*(12992+(7006+(1565+(130+3*n)*n)*n)*n)/16:
    seq(a(n), n=0..40);

Formula

G.f.: (194*x^4-713*x^3-5*x^2+113*x+1356)*x/(1-x)^11.
a(n) = C(n+5,6)*(3*n^4+130*n^3+1565*n^2+7006*n+12992)/16.