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A329890
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a(1) = 1; for n > 1, a(n) = sigma((2^n)-1) - sigma((2^(n-1))-1), where sigma is A000203, the sum of divisors.
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4
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1, 3, 4, 16, 8, 72, 24, 304, 160, 944, 624, 6576, -544, 14336, 16384, 72544, 19616, 342528, 50688, 1475584, 466176, 3443712, 2657376, 29486880, -3340288, 54808448, 65971360, 306781024, 77647680, 1475408064, 132153344, 5157119680, 3054411072, 12548176896, 13343981568, 130039259136, -28235160128, 228451400256, 269821673472
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OFFSET
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1,2
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LINKS
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FORMULA
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PROG
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(PARI) A329890(n) = if(1==n, 1, sigma((2^n)-1)-sigma((2^(n-1))-1));
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CROSSREFS
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From second term onwards, the first differences of A075708.
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KEYWORD
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sign
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AUTHOR
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STATUS
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approved
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