%I
%S 1,35,215,225,398,2097,5205,7452,22359,98176,169653
%N Sum of first n^2 odd primes (=S) is divisible by n and S/n = n mod 2.
%C A necessary condition for the existence of a magic square consisting of the first n^2 odd primes.
%C a(12) > 500000.  Donovan Johnson
%e a(2)=35 since 3+5+ ... +9941 = 5706505 = 35*163043 and 163043 = 35 mod 2.
%o (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,))
%K nonn,hard
%O 1,2
%A H. K. Gottlob Maier (1korrago(AT)freenet.de), Sep 07, 2001
%E a(10)a(11) from _Donovan Johnson_, Nov 30 2010
