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 1-5 of 5 results.

A176692 Partial sums of A000617.

Original entry on oeis.org

2, 5, 10, 20, 47, 166, 1279, 30654, 2760820
Offset: 0

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Author

Jonathan Vos Post, Apr 24 2010

Keywords

Comments

Partial sums of number of NP-equivalence classes of threshold functions of n or fewer variables. The subsequence of primes in this sequence begins: 2, 5, 47, 1279.

Examples

			a(6) = 2 + 3 + 5 + 10 + 27 + 119 + 1113 = 1279 is prime.
		

Crossrefs

Formula

a(n) = SUM[i=0..n] A000617(i) = SUM[i=0..n] SUM[j=0..i] A000619(j).

A000619 NP-equivalence classes of threshold functions of exactly n variables.

Original entry on oeis.org

2, 1, 2, 5, 17, 92, 994, 28262, 2700791, 990331318
Offset: 0

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Author

Keywords

References

  • S. Muroga, Threshold Logic and Its Applications. Wiley, NY, 1971, p. 38, Table 2.3.2. - Row 15.
  • S. Muroga, T. Tsuboi and C. R. Baugh, Enumeration of threshold functions of eight variables, IEEE Trans. Computers, 19 (1970), 818-825.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A000617.

Formula

a(n) = A000617(n) - A000617(n-1). - Alastair D. King, Oct 26 2023.

Extensions

a(9) added by Xavier Molinero, Oct 06 2021

A001532 Number of NP-equivalence classes of self-dual threshold functions of n or fewer variables ; number of majority (i.e., decisive and weighted) games with n players.

Original entry on oeis.org

1, 1, 2, 3, 7, 21, 135, 2470, 175428, 52980624
Offset: 1

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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.)
  • D. E. Knuth, The Art of Computer Programming, Vol. 4A, Section 7.1.1, p. 79.
  • S. Muroga, Threshold Logic and Its Applications. Wiley, NY, 1971, p. 38, Table 2.3.2. - Row 23. (Cases until n=9.)
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
  • J. von Neumann and O. Morgenstern, Theory of games and economic behavior, Princeton University Press, New Jersey, 1944. (Cases n=1 to 5.)

Crossrefs

Formula

a(n) = Sum_{k=1..n} A003184(k). - Alastair D. King, Oct 26 2023

Extensions

a(10) added by W. Lan (wl(AT)fjrtvu.edu.cn), Jun 27 2010
Better description from Alastair King, Mar 17 2023.

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

A109455 Number of equivalence classes of threshold functions under permutations of the variables.

Original entry on oeis.org

2, 4, 10, 34, 178, 1720, 590440
Offset: 0

Views

Author

Don Knuth, Aug 17 2005

Keywords

References

  • D. E. Knuth, The Art of Computer Programming, Vol. 4A, Section 7.1.1, p. 79.
  • S. Muroga, Threshold Logic and Its Applications. Wiley, NY, 1971. [Background]

Crossrefs

Showing 1-5 of 5 results.