A278419 - OEIS

A278419

Decimal expansion of sum of cubes of reciprocals of nonprime numbers.

1, 0, 2, 7, 2, 9, 4, 2, 6, 3, 8, 6, 0, 1, 5, 0, 7, 4, 8, 9, 7, 6, 6, 2, 4, 8, 4, 6, 8, 4, 5, 7, 4, 3, 2, 8, 9, 7, 8, 9, 5, 7, 4, 1, 7, 0, 4, 1, 4, 3, 4, 9, 5, 9, 1, 9, 0, 3, 5, 9, 9, 5, 3, 8, 6, 4, 0, 2, 0, 6, 6, 1, 6, 2, 5, 8, 1, 8, 3, 5, 0, 2, 5, 5, 0, 8, 2, 1, 6, 7, 3, 0, 7, 2, 3, 6, 2, 6, 9, 7, 5, 9, 9, 4

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OFFSET

1,3

LINKS

Table of n, a(n) for n=1..104.

Eric Weisstein's World of Mathematics, Zeta Function.

Eric Weisstein's World of Mathematics, Prime Zeta Function.

FORMULA

Sum_{n>=1} 1/n^3 - Sum_{n>=1} 1/prime(n)^3.

Equals zeta(3) - primezetaP(3).

Sum of cubes of reciprocals of composite numbers = zeta(3) - primezetaP(3) - 1 = 0.02729426386...

EXAMPLE