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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 I. Strazdins, Universal affine classification of Boolean functions, Acta Applic. Math. 46 (1997), 147-167. Index entries for linear recurrences with constant coefficients, signature (6,-8). FORMULA Appears to be 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 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 October 16 19:22 EDT 2018. Contains 316271 sequences. (Running on oeis4.)