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 1-6 of 6 results.

A002077 Number of N-equivalence classes of self-dual threshold functions of exactly n variables.

Original entry on oeis.org

1, 0, 1, 4, 46, 1322, 112519, 32267168, 34153652752
Offset: 1

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Author

Keywords

References

  • S. Muroga, Threshold Logic and Its Applications. Wiley, NY, 1971, p. 38, Table 2.3.2. - Row 10.
  • S. Muroga and I. Toda, Lower bound on the number of threshold functions, IEEE Trans. Electron. Computers, 17 (1968), 805-806.
  • 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

Formula

A002080(n) = Sum_{k=1..n} a(k)*binomial(n,k). Also A000609(n-1) = Sum_{k=1..n} a(k)*binomial(n,k)*2^k. - Alastair D. King, Mar 17 2023.

Extensions

Better description from Alastair King, Mar 17 2023

A000609 Number of threshold functions of n or fewer variables.

Original entry on oeis.org

2, 4, 14, 104, 1882, 94572, 15028134, 8378070864, 17561539552946, 144130531453121108
Offset: 0

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Author

Keywords

Comments

a(n) is also equal to the number of self-dual threshold functions of n+1 or fewer variables. - Alastair D. King, Mar 17 2023.

References

  • Sze-Tsen Hu, Threshold Logic, University of California Press, 1965 see page 57.
  • 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 3.
  • 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).
  • C. Stenson, Weighted voting, threshold functions, and zonotopes, in The Mathematics of Decisions, Elections, and Games, Volume 625 of Contemporary Mathematics Editors Karl-Dieter Crisman, Michael A. Jones, American Mathematical Society, 2014, ISBN 0821898663, 9780821898666

Crossrefs

Formula

a(n) = Sum_{k=0..n} A000615(k)*binomial(n,k) = Sum_{k=0..n} A002079(k)*binomial(n,k)*2^k. Also A002078(n) = (1/2^n)*Sum_{k=0..n} a(k)*binomial(n,k), a(n-1) = Sum_{k=1..n} A002077(k)*binomial(n,k)*2^k, and A002080(n) = (1/2^n)*Sum_{k=1..n} a(k)*binomial(n,k). - Alastair D. King, Mar 17 2023.

Extensions

a(9) from Minfeng Wang, Jun 27 2010

A002080 Number of N-equivalence classes of self-dual threshold functions of n or fewer variables.

Original entry on oeis.org

1, 2, 4, 12, 81, 1684, 122921, 33207256, 34448225389
Offset: 1

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Author

Keywords

References

  • S. Muroga, Threshold Logic and Its Applications. Wiley, NY, 1971, p. 38 and 214.
  • 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

Formula

a(n) = Sum_{k=1..n} A002077(k)*binomial(n,k) = (1/2^n)*Sum_{k=1..n} A000609(k-1)*binomial(n,k). - Alastair D. King, Mar 17 2023.

Extensions

Better description and corrected value of a(7) from Alastair King (see link) - N. J. A. Sloane, Oct 24 2023

A002079 Number of N-equivalence classes of threshold functions of exactly n variables.

Original entry on oeis.org

2, 1, 2, 9, 96, 2690, 226360, 64646855, 68339572672
Offset: 0

Views

Author

Keywords

References

  • S. Muroga, Threshold Logic and Its Applications. Wiley, NY, 1971, p. 38, Table 2.3.2. - Row 8.
  • 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

Formula

A002078(n) = Sum_{k=0..n} a(k)*binomial(n,k). A000609(n) = Sum_{k=0..n} a(k)*binomial(n,k)*2^k. - Alastair D. King, Mar 17 2023.

Extensions

Better description from Alastair King, Mar 17 2023.

A001529 NPN-equivalence classes of threshold functions of n or fewer variables.

Original entry on oeis.org

1, 2, 3, 6, 15, 63, 567, 14755, 1366318
Offset: 0

Views

Author

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, p. 38, Table 2.3.2. - Row 19.
  • 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

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 1-6 of 6 results.