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A028403
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Number of types of Boolean functions of n variables under a certain group.
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12
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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
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OFFSET
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1,1
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LINKS
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FORMULA
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a(n) = 6*a(n-1) - 8*a(n-2).
G.f.: 4*x*(1 - 3*x)/((1-2*x)*(1-4*x)). (End)
E.g.f.: (1/2)*(exp(2*x) -1)*(exp(2*x) + 3). - G. C. Greubel, Jul 07 2021
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MATHEMATICA
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Join[{4}, Table[FromDigits[Join[{1}, PadRight[{}, n-2, 0], {1}, PadRight[ {}, n, 0]], 2], {n, 2, 30}]] (* Harvey P. Dale, Jan 24 2021 *)
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PROG
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(PARI) Vec(4*x*(1-3*x)/((1-2*x)*(1-4*x)) + O(x^100)) \\ Colin Barker, Sep 30 2014
(Magma) [2^(2*n-1) +2^n: n in [1..30]]; // G. C. Greubel, Jul 07 2021
(Sage) [2^(2*n-1) +2^n for n in (1..30)] # G. C. Greubel, Jul 07 2021
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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