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A199858
Decimal expansion of Sum_{n = 1 .. infinity }[ 1 / Sum {i = 1 .. m} d(i)^n] where d(i) are the divisors of n and m = tau(n) is the number of divisors of n.
1
1, 2, 3, 9, 7, 1, 9, 5, 3, 8, 1, 4, 6, 2, 2, 7, 4, 1, 1, 9, 6, 5, 0, 4, 2, 6, 7, 6, 5, 2, 4, 5, 8, 7, 1, 0, 4, 6, 7, 9, 0, 0, 0, 3, 6, 4, 6, 2, 3, 5, 4, 2, 7, 4, 1, 4, 2, 9, 5, 8, 6, 3, 0, 5, 7, 6, 9, 8, 9, 8, 3, 3, 8, 1, 7, 1, 7, 6, 5, 2, 1, 5, 0, 9, 6, 0, 2, 6, 2, 4, 8, 4, 8, 9, 7, 7, 1, 1, 4, 7, 6, 8, 7, 0, 3
OFFSET
1,2
EXAMPLE
1.23971953814622741196504267652458710467...
MATHEMATICA
RealDigits[N[Sum[1/DivisorSigma[n, n], {n, 1, 100}], 130]][[1]]
CROSSREFS
Sequence in context: A288842 A108694 A267896 * A357053 A340442 A199963
KEYWORD
nonn,cons
AUTHOR
Michel Lagneau, Nov 28 2011
STATUS
approved