A109580 Primes in A109579.

3, 3, 7, 7, 11, 11, 11, 11, 13, 13, 17, 17, 17, 17, 23, 23, 29, 29, 29, 29, 61, 61, 71, 71, 71, 71, 83, 83, 83, 83, 83, 83, 107, 107, 107, 107, 137, 137, 137, 137, 137, 137, 137, 137, 149, 149, 193, 193, 227, 227, 227, 227, 227, 227, 241, 241, 241, 241, 281, 281, 307

Offset: 1

Author

Roger L. Bagula, Jun 29 2005

Keywords

• nonn

Crossrefs

Cf. A001223, A010051.

Programs

Maple

with(numtheory): a:=proc(n) if isprime(sum((pi(k+1)-pi(k))*(ithprime(k+1)-ithprime(k)),k=1..n))=true then sum((pi(k+1)-pi(k))*(ithprime(k+1)-ithprime(k)),k=1..n) else fi end: seq(a(n),n=1..230);

Mathematica

an = Table[(PrimePi[n + 1] - PrimePi[n])*(Prime[n + 1] - Prime[n]), {n, 1, 400}] a[0] = 0; a[n_] := a[n] = a[n - 1] + an[[n]] aa = Flatten[Table[If[PrimeQ[a[n]] == True, a[n], {}], {n, 0, Length[an]}]]