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A355694
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Dirichlet inverse of A277791, denominator of sum of reciprocals of proper divisors of n.
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2
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1, -1, -1, -1, -1, -4, -1, -1, -2, -8, -1, 9, -1, -12, -13, -1, -1, 6, -1, 1, -19, -20, -1, -10, -4, -24, -4, 1, -1, 26, -1, -1, -31, -32, -33, 27, -1, -36, -37, 10, -1, 34, -1, 1, -12, -44, -1, 35, -6, 2, -49, 1, -1, -14, -53, 62, -55, -56, -1, 87, -1, -60, -18, -1, -63, 110, -1, 1, -67, 42, -1, -57, -1, -72, 12
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OFFSET
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1,6
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LINKS
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FORMULA
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a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, d<n} A277791(n/d) * a(d).
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PROG
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(PARI)
memoA355694 = Map();
A355694(n) = if(1==n, 1, my(v); if(mapisdefined(memoA355694, n, &v), v, v = -sumdiv(n, d, if(d<n, A277791(n/d)*A355694(d), 0)); mapput(memoA355694, n, v); (v)));
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CROSSREFS
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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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