A283071 Decimal expansion of the density of integers that are divisible by the square of their least prime factor.

3, 3, 0, 0, 9, 8, 0, 3, 5, 3, 9, 0, 0, 2, 2, 1

Offset

0,1

Links

Table of n, a(n) for n=0..15.

Formula

1/2^2 + (1/2)/3^2 + (1/2)*(2/3)/5^2 + (1/2)*(2/3)*(4/5)/7^2 + (1/2)*(2/3)*(4/5)*(6/7)/11^2 + ....

Example

0.3300980353900221...

Prog

(PARI) primezeta(s)=my(t=s*log(2), iter=lambertw(t/eps())\t); sum(k=1, iter, moebius(k)/k*log(abs(zeta(k*s))))
Pz=primezeta(2); s=0; t=1.; forprime(p=2, 1e10, Pz-=1/p^2; s+=t/p^2; t*=1-1/p); s+t*Pz

Crossrefs

Cf. A283050.

Sequence in context: A338034 A299904 A221768 * A060523 A199041 A199237

Adjacent sequences: A283068 A283069 A283070 * A283072 A283073 A283074

Keyword

nonn,cons,more

Author

Charles R Greathouse IV and Michel Marcus, Feb 28 2017

Status

approved