A114519 a(n) = A008475(A114518(n)).

2, 3, 5, 5, 7, 7, 11, 7, 13, 17, 11, 19, 13, 23, 11, 11, 29, 31, 19, 13, 37, 13, 41, 43, 47, 19, 17, 53, 29, 31, 59, 61, 67, 71, 17, 73, 23, 79, 43, 83, 19, 89, 97, 29, 101, 103, 107, 31, 109, 23, 113, 61, 127, 131, 137, 139, 73, 41, 149, 151, 157, 37, 83, 163, 19, 167, 47

Offset

1,1

Links

Nathaniel Johnston, Table of n, a(n) for n = 1..10000

Example

A114518(15) = 24 = 2^3 * 3 and 2^3 + 3 = 11 (which is prime). So a(15) = 11.

Mathematica

f[n_] := Plus @@ Power @@@ FactorInteger[n]; Select[f /@ Range[175], PrimeQ[ # ] &] (* Ray Chandler, Dec 07 2005 *)

Prog

(PARI) A008475(n)=local(t); if(n<1, 0, t=factor(n); sum(k=1, matsize(t)[1], t[k, 1]^t[k, 2])); for(i=1, 500, if(isprime(A008475(i)), print1(A008475(i), ", "))) (Herrgesell)

Crossrefs

Cf. A008475, A114518.

Sequence in context: A222312 A344404 A298676 * A126762 A082048 A113459

Adjacent sequences: A114516 A114517 A114518 * A114520 A114521 A114522

Keyword

nonn

Author

Leroy Quet, Dec 05 2005

Extensions

Extended by Ray Chandler and Lambert Herrgesell (zero815(AT)googlemail.com), Dec 07 2005

Status

approved