A160358 Indices of primes in A133547, i.e., numbers n such that the sum of the squares of the first n odd primes is prime.

3, 5, 9, 11, 23, 29, 63, 65, 71, 95, 141, 159, 161, 173, 179, 183, 209, 219, 255, 299, 323, 341, 365, 371, 389, 393, 453, 485, 521, 567, 579, 605, 623, 633, 635, 639, 677, 701, 711, 723, 725, 747, 785, 827, 867, 945, 981, 993, 999, 1001, 1013, 1035, 1037, 1041

Offset: 1

Author

M. F. Hasler, May 18 2009

Keywords

• nonn

Comments

All terms are necessarily odd. Thus one could also consider the sequence floor(a(n)/2) = (1,2,4,5,11,14,31,32,35,...). Other possible variations would be to list the index a(n)+1 of the largest prime in that sum, or, since this is always even, (a(n)+1)/2 = (2,3,5,6,12,15,32,33,36,...).

Crossrefs

Cf. A098561, A133547.

Programs

PARI

s=0; for( i=2,1999, isprime(s+=prime(i)^2) & print1(i-1,","))

Formula

A160359(n) = A133547(a(n)) = A024450(a(n)+1) - 4.