A098561 Numbers n such that the sum of the squares of the first n primes is prime.

2, 18, 26, 36, 68, 78, 144, 158, 164, 174, 192, 212, 216, 236, 264, 288, 294, 338, 344, 356, 384, 404, 416, 426, 500, 516, 518, 522, 534, 540, 548, 614, 678, 680, 782, 858, 866, 876, 878, 896, 900, 912, 950, 974, 996, 1064, 1080, 1082, 1100, 1122, 1158, 1160

Offset: 1

Author

Rick L. Shepherd, Sep 14 2004

Keywords

• nonn

Comments

a(n) must clearly be even.

Examples

			2 is a term as the sum of the squares of the first two primes is 2^2 + 3^2 = 13, which is prime.
		

Links

• Zak Seidov, Table of n, a(n) for n = 1..1050

Crossrefs

Cf. A098562 (corresponding primes), A024450 (sums of squares of primes), A098563 (sums of cubes of primes), A013916 (sums of primes).

Programs

Mathematica

Select[Range[1000], PrimeQ[Sum[Prime[i]^2, {i, #}]] &] (* Carl Najafi, Aug 22 2011 *)