0,2

These are invertible maps from {0,1}^n to {0,1}^n, or in other words permutations of the 2^n binary vectors of length n.

2^n-th order derivative of n-th Mandelbrot iterate. Example: a(2) = 24, after one iterate in the Mandelbrot(z(n+1) = z(n)^2 + c) we have the function z(2) = z^4 + 2*c*z^2 + c^2 + c, for which the 4-th order derivative is 24. - Bert van den Bosch (zeusooooo(AT)hotmail.com), Sep 07 2003

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

C. S. Lorens, Invertible Boolean functions, IEEE Trans. Electron. Computers, EC-13 (1964), 529-541.

I. Strazdins, Universal affine classification of Boolean functions, Acta Applic. Math. 46 (1997), 147-167.

Index entries for sequences related to Boolean functions

a(n) = (2^n)!.

Sum of reciprocals = 0.54169146825401604874... - Cino Hilliard (hillcino368(AT)gmail.com), Feb 08 2003

(PARI) atonfact(a, n) = {sr=0; for(x=1, n, y =(a^x)!; sr+=1.0/y; print1(y" "); ); print(); print(sr) }

Cf. A001038 A000653 A000654 A000652 A001537 A046856 A046857

Sequence in context: A062716 A137888 A108349 this_sequence A098679 A123851 A120122

Adjacent sequences: A000719 A000720 A000721 this_sequence A000723 A000724 A000725

nonn,easy

N. J. A. Sloane (njas(AT)research.att.com).