%I A033998
%S A033998 23,22073,67187,79427,10729219,3531577135439
%N A033998 Numbers n such that the sum of the primes <= n is a square.
%H A033998 G. L. Honaker Jr. and C. Caldwell, <a href="http://primes.utm.edu/curios/
               page.php?curio_id=179">Prime Curios!: 9</a>
%H A033998 G. L. Honaker Jr. and C. Caldwell, <a href="http://primes.utm.edu/curios/
               page.php?curio_id=12250">Prime Curios!: 3531577135439</a>
%H A033998 C. Riveras, PrimePuzzles.Net, <a href="http://www.primepuzzles.net/puzzles/
               puzz_009.htm">Problem 9: Sum of first k primes is perfect square</
               a>
%F A033998 a(n) = Prime(A033997(n))
%e A033998 2+3+5+7+11+13+17+19+23 = 10^2 is a square, so 23 is in the sequence.
%Y A033998 Cf. A000040, A033997, A061888, A061890.
%Y A033998 Sequence in context: A090674 A013728 A028693 this_sequence A157167 A101699 
               A122148
%Y A033998 Adjacent sequences: A033995 A033996 A033997 this_sequence A033999 A034000 
               A034001
%K A033998 nonn
%O A033998 1,1
%A A033998 Calculated by Jud McCranie (j.mccranie(AT)comcast.net)
%E A033998 3531577135439 from Giovanni Resta (g.resta(AT)iit.cnr.it), May 27 2003
%E A033998 Edited by Ray Chandler (rayjchandler(AT)sbcglobal.net), Mar 20 2007