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.

Showing 1-2 of 2 results.

A091479 Number of graphs with n nodes. Nodes and edges labeled each from their own label set.

Original entry on oeis.org

1, 1, 2, 16, 1957, 9864101, 3554627472076, 138879579704209680022, 828772446866981044847857913441, 1011182700521015817607065606491025592595137, 325166909258549255903203528672831330994640286650913570126
Offset: 0

Views

Author

Christian G. Bower, Jan 13 2004

Keywords

Crossrefs

Row sums of A091478.
Cf. A006125.

Programs

  • PARI
    a(n)={binomial(n,2)!*sum(k=0, binomial(n,2), 1/k!)} \\ Andrew Howroyd, Feb 12 2020

Formula

a(n) = A000522(A000217(n-1)). - Gerald McGarvey, Nov 17 2007

Extensions

a(0)=1 prepended and terms a(10) and beyond from Andrew Howroyd, Feb 12 2020

A091480 Table of multigraphs (by antidiagonals) with n (>=1) nodes and k (>=0) edges. Each type of object labeled from its own label set.

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 0, 1, 3, 1, 0, 1, 9, 6, 1, 0, 1, 27, 36, 10, 1, 0, 1, 81, 216, 100, 15, 1, 0, 1, 243, 1296, 1000, 225, 21, 1, 0, 1, 729, 7776, 10000, 3375, 441, 28, 1, 0, 1, 2187, 46656, 100000, 50625, 9261, 784, 36, 1, 0, 1, 6561, 279936, 1000000, 759375
Offset: 1

Views

Author

Christian G. Bower, Jan 13 2004

Keywords

Examples

			1  0   0    0     0 ...
1  1   1    1     1 ...
1  3   9   27    81 ...
1  6  36  216  1296 ...
1 10 100 1000 10000 ...
		

References

  • F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and Tree-Like Structures, Cambridge, 1998, p. 114 (2.4.44).

Crossrefs

Columns 0-8: A000012, A000217(n-1), A000537(n-1), A059827(n-1), A059977(n-1), A059860(n-1), A059978(n-1), A059979(n-1), A059980(n-1).
Cf. A091478.

Formula

a(n, k) = binomial(n, 2)^k.
Showing 1-2 of 2 results.