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.

A005530 Number of Boolean functions of n variables from Post class F(8,inf); number of degenerate Boolean functions of n variables.

Original entry on oeis.org

2, 6, 38, 942, 325262, 25768825638, 129127208425774833206, 2722258935367507707190488025630791841374
Offset: 1

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Keywords

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
  • I. Tomescu, Introducere in Combinatorica. Editura Tehnica, Bucharest, 1972, p. 129.

Crossrefs

a(n) = 2^(2^n) - A000371(n). Cf. A036239, A036240.

Programs

  • Mathematica
    Sum[(-1)^(j + 1) Binomial[n, j] 2^2^(n - j), {j, 1, n}]
  • PARI
    for(n=1,10, print1(sum(j=1,n, (-1)^(j+1)*binomial(n,j)*2^(2^(n-j))), ", ")) \\ G. C. Greubel, Oct 06 2017

Formula

a(n) = Sum_{j=1..n} (-1)^(j+1)*binomial(n,j)*2^(2^(n-j)).

Extensions

More terms from Vladeta Jovovic, Goran Kilibarda