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A195460
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a(n) = 2^(2*n+1) - 3*2^n - 1.
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2
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1, 19, 103, 463, 1951, 7999, 32383, 130303, 522751, 2094079, 8382463, 33542143, 134193151, 536821759, 2147385343, 8589737983, 34359345151, 137438167039, 549754241023, 2199020109823, 8796086730751, 35184359505919, 140737463189503
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OFFSET
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1,2
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COMMENTS
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Binary numbers of the form (n)00(m) where n and m are the number of 1's, m is the index and n=m-1.
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LINKS
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FORMULA
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G.f.: x*(1+12*x-16*x^2)/((1-x)*(1-2*x)*(1-4*x)). - Bruno Berselli, Sep 19 2011
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EXAMPLE
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First few terms in binary are 1, 10011, 1100111, 111001111, 11110011111, 1111100111111.
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PROG
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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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STATUS
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approved
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