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A028403 Number of types of Boolean functions of n variables under a certain group. 11
4, 12, 40, 144, 544, 2112, 8320, 33024, 131584, 525312, 2099200, 8392704, 33562624, 134234112, 536903680, 2147549184, 8590065664, 34360000512, 137439477760, 549756862464, 2199025352704, 8796097216512, 35184380477440, 140737505132544, 562949986975744 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(1) written in base 2: 100 (A163450(1)). a(n) for n >= 2 written in base 2: 1100, 101000, 10010000, 1000100000, ..., i.e. number 1, (n-2) times 0, number 1 and n times 0 (A163450(n) for n >= 2). - Jaroslav Krizek, Jul 27 2009

LINKS

Table of n, a(n) for n=1..25.

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

Index entries for sequences related to Boolean functions

Index entries for linear recurrences with constant coefficients, signature (6,-8).

FORMULA

a(n) = (2^(n-1) + 1)*2^n = 2*A007582(n-1). - Ralf Stephan, Mar 24 2004

a(n) = A000079(n) * (A000079(n-1) + 1) = (A000051(n) - 1) * A000051(n-1) = A000079(n) * A000051(n-1) = (A000051(n) - 1) * (A000079(n-1) + 1) = 2^n * (2^(n-1) + 1). a(n+1) = A000079(n+1) * (A000079(n) + 1) = (A000051(n+1) - 1) * A000051(n) = A000079(n+1) * A000051(n) = (A000051(n+1) - 1) * (A000079(n) + 1) = 2^(n+1) * (2^n + 1). a(n) = A081294(n) + A000079(n) = A004171(n-1) + A000079(n) = 2^(2n-1) + 2^n. - Jaroslav Krizek, Jul 27 2009

a(n) = 6*a(n-1)-8*a(n-2). G.f.: -4*x*(3*x-1) / ((2*x-1)*(4*x-1)). - Colin Barker, Sep 30 2014

PROG

(PARI) Vec(-4*x*(3*x-1)/((2*x-1)*(4*x-1)) + O(x^100)) \\ Colin Barker, Sep 30 2014

CROSSREFS

Sequence in context: A149333 A074450 A074032 * A149334 A149335 A149336

Adjacent sequences:  A028400 A028401 A028402 * A028404 A028405 A028406

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Vladeta Jovovic, Feb 24 2000

More terms from Colin Barker, Sep 30 2014

STATUS

approved

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Last modified November 30 15:27 EST 2020. Contains 338807 sequences. (Running on oeis4.)