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

1,1

Links

Table of n, a(n) for n=1..61.

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]}]]

Crossrefs

Cf. A001223, A010051.

Sequence in context: A088147 A302446 A109579 * A168269 A326936 A336416

Adjacent sequences: A109577 A109578 A109579 * A109581 A109582 A109583

Keyword

nonn

Author

Roger L. Bagula, Jun 29 2005

Status

approved