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

1,1

Comments

a(n) must clearly be even.

Links

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

Example

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

Mathematica

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

Crossrefs

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

Sequence in context: A031104 A115042 A191461 * A141426 A101844 A193598

Adjacent sequences: A098558 A098559 A098560 * A098562 A098563 A098564

Keyword

nonn

Author

Rick L. Shepherd, Sep 14 2004

Status

approved