The On-Line Encyclopedia of Integer Sequences (OEIS)

A002080 revision #45

A002080

Number of N-equivalence classes of self-dual threshold functions of n or fewer variables.
(Formerly M1266 N0485)

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

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OFFSET

1,2

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).

LINKS

S. Muroga, Threshold Logic and Its Applications, Wiley, NY, 1971. [Annotated scans of a few pages]

S. Muroga, T. Tsuboi and C. R. Baugh, Enumeration of threshold functions of eight variables, IEEE Trans. Computers, 19 (1970), 818-825. [Annotated scanned copy]

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.

CROSSREFS

KEYWORD

nonn,more

AUTHOR

EXTENSIONS

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

STATUS

editing