%I A064013
%S A064013 1,35,215,225,398,2097,5205,7452,22359
%N A064013 Sum of first n^2 odd primes (=S) is divisible by n and S/n = n mod 2.
%C A064013 A necessary condition for the existence of a magic square consisting 
               of the first n^2 odd primes.
%e A064013 a(2)=35 since 3+5+ ... +9941 = 5706505 = 35*163043 and 163043 = 35 mod 
               2.
%o A064013 (PARI) s=0; t=0; u=1; forprime(x=3,2500000,s=s+x; t=t+1; if(t==u*u, if(s%u==0&(s\u)%2==u%2,
               print(u),); u=u+1,))
%Y A064013 Sequence in context: A005937 A007329 A101628 this_sequence A020262 A104474 
               A068722
%Y A064013 Adjacent sequences: A064010 A064011 A064012 this_sequence A064014 A064015 
               A064016
%K A064013 nonn,hard
%O A064013 1,2
%A A064013 H. K. Gottlob Maier (1korrago(AT)freenet.de), Sep 07, 2001