A120483 Decimal expansion of s = sum_{i=1..infinity} (1/c(i))^i, where c(i) is the i-th composite number.

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

Offset

1,1

Links

Table of n, a(n) for n=1..100.

Example

Sum is (1/4)^1 + (1/6)^2 + (1/8)^3 + (1/9)^4 + (1/10)^5 + ... = 0.279893663...

Mathematica

k = s = 0; Do[If[ !PrimeQ[n], k++; s += (1/n)^k], {n, 2, 100}]; First[RealDigits[N[s, 100]]]

Crossrefs

Sequence in context: A339237 A363078 A114940 * A124823 A086725 A019950

Adjacent sequences: A120480 A120481 A120482 * A120484 A120485 A120486

Keyword

cons,nonn

Author

Ryan Propper, Jul 21 2006

Status

approved