A109554 pi(n)[prime(n+1)-prime(n)], where pi(n) is the number of prime numbers less than or equal to n and prime(k) is the k-th prime.

0, 2, 4, 8, 6, 12, 8, 16, 24, 8, 30, 20, 12, 24, 36, 36, 14, 42, 32, 16, 48, 32, 54, 72, 36, 18, 36, 18, 40, 140, 44, 66, 22, 110, 22, 66, 72, 48, 72, 72, 26, 130, 28, 56, 28, 168, 180, 60, 30, 60, 90, 30, 160, 96, 96, 96, 32, 96, 68, 34, 180, 252, 72, 36, 72, 252, 114, 190, 38

Offset

1,2

Links

Table of n, a(n) for n=1..69.

Example

a(2)=pi(2)[prime(3)-prime(2)]=1*(5-3)=2.

Maple

with(numtheory): a:=n->pi(n)*(ithprime(n+1)-ithprime(n)): seq(a(n), n=1..70);

Mathematica

a = Table[(Prime[n + 1] - Prime[n])*PrimePi[n], {n, 1, 200}]

Crossrefs

Sequence in context: A125597 A366170 A151732 * A339821 A269382 A253886

Adjacent sequences: A109551 A109552 A109553 * A109555 A109556 A109557

Keyword

nonn

Author

Roger L. Bagula, Jun 27 2005

Status

approved