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.

A058737 Main diagonal of A058735.

Original entry on oeis.org

1, 1, 3, 7, 20, 55, 162, 477, 1450, 4446, 13858, 43589, 138515, 443487, 1430261, 4640312, 15137893, 49620637, 163360133, 539904503, 1790699059, 5958280016, 19883532941, 66532519727, 223177199775, 750340752081, 2528058240115
Offset: 2

Views

Author

N. J. A. Sloane, Jan 01 2001

Keywords

Comments

Also the number of unlabeled cographs on n nodes with two components. - Vladeta Jovovic, May 07 2005

References

  • J. Riordan, The blossoming of Schroeder's fourth problem, Acta Math., 137 (1976), 1-16.

Links

Crossrefs

Cf. A000669, A058735, A106240.

Formula

G.f.: A(x) = (B(x)^2 + B(x^2))/2, where B(x) = g.f. for A000669. - Vladeta Jovovic, May 07 2005

Extensions

More terms from Vladeta Jovovic, May 07 2005

A106606 G.f.: 1/Product_{k>0} (1-x^k)^A000669(k+1).

Original entry on oeis.org

1, 1, 3, 8, 23, 66, 199, 601, 1861, 5815, 18396, 58684, 188764, 611103, 1990361, 6515786, 21429510, 70767468, 234565319, 780086526, 2602209961, 8704547698, 29191435328, 98125474137, 330558122499, 1115795428615, 3773380090126, 12782934685768, 43374552366876
Offset: 0

Views

Author

Washington Bomfim and Vladeta Jovovic, May 10 2005

Keywords

Comments

k-th row of A058735 as k tends to infinity.

Crossrefs

Cf. A106240.

Extensions

More terms from R. J. Mathar, Feb 13 2008
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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