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 1-3 of 3 results.

A109456 Number of Boolean functions of n variables that are self-dual and regular.

Original entry on oeis.org

0, 1, 1, 2, 3, 7, 21, 135, 2470, 319124, 1214554343, 1706241214185942
Offset: 0

Views

Author

Don Knuth, Aug 17 2005

Keywords

Comments

Or, number of self-dual 2-monotonic Boolean functions of n or fewer variables.
Agrees with A001532 for n <= 8 but then diverges.
The value for n=10 was calculated with BDD techniques; all solutions are characterized by a binary decision diagram with 30011986 nodes.
The value for n=11 was calculated by Minfeng Wang in May 2012 (see [Hausmann & Rodriguez]). The news was published by J.-C. Hausmann (2015). - Fabián Riquelme, Mar 19 2018
For n from 1 to 9, a(n) agrees with the number of directed zero-sum games with n players in Table 1 of Krohn and Sudhölter. - Peter Bala, Dec 16 2021

References

  • D. E. Knuth, The Art of Computer Programming, Vol. 4, Section 7.1.1 (in preparation).

Extensions

a(10) from Don Knuth, Feb 06 2008
a(11) from Fabián Riquelme, Mar 27 2018

A189359 Number of homogeneous games for n players.

Original entry on oeis.org

0, 1, 3, 8, 23, 76, 293, 1307, 6642, 37882
Offset: 0

Views

Author

Fabián Riquelme, Apr 20 2011

Keywords

Crossrefs

Subclass of A000617. Cf. A001532, A022493, A109456, A132183.

Formula

Conjecture: g.f.: Q(0)*x/(1-x), where Q(k) = 1 + (1-(1-x)^(2*k+2))/(1- (1-(1-x)^(2*k+3))/(1-(1-x)^(2*k+3) + 1/Q(k+1))); (continued fraction). - Sergei N. Gladkovskii, May 13 2013
Note that a(n) - a(n-1) = A022493(n) for 1 <= n <= 9. Does this equality hold for n > 9? If so, then we have the g.f. 1/(1 - x)*( Sum_{n >= 1} Product_{k = 1..n} (1 - (1 - x)^k) ). - Peter Bala, Dec 13 2021

A003184 Number of NP-equivalence classes of self-dual threshold functions of exactly n variables.

Original entry on oeis.org

1, 0, 1, 1, 4, 14, 114, 2335, 172958, 52805196
Offset: 1

Views

Author

Keywords

References

  • H. M. Gurk and J. R. Isbell. 1959. Simple Solutions. In A. W. Tucker and R. D. Luce (eds.) Contributions to the Theory of Games, Volume 4. Princeton, NJ: Princeton University Press, pp. 247-265. Case n=6.
  • S. Muroga, Threshold Logic and Its Applications. Wiley, NY, 1971, p. 38, Table 2.3.2. - Row 24. (Cases n>7.)
  • J. von Neumann and O. Morgenstern, Theory of games and economic behavior, Princeton University Press, New Jersey, 1944. Cases n=1 to 5.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Formula

a(n) = A001532(n) - A001532(n-1), for n > 1. - Evgeny Luttsev, Sep 09 2014

Extensions

a(9) from Evgeny Luttsev, Sep 09 2014
Better description and new offset from Alastair King, Mar 17 2023
Showing 1-3 of 3 results.