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A098561
Numbers n such that the sum of the squares of the first n primes is prime.
12
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.
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: A115042 A191461 A366957 * A141426 A101844 A193598
KEYWORD
nonn
AUTHOR
Rick L. Shepherd, Sep 14 2004
STATUS
approved