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Perfect squares which are neither the sum nor the difference of two primes.
12

%I #7 Mar 31 2012 14:11:37

%S 121,289,529,625,961,1681,2601,2809,3481,4225,4489,5329,6241,6889,

%T 7225,7569,8281,9025,9409,10201,11881,12769,13225,15625,16641,17689,

%U 18769,19881,20449,22201,22801,23409,24649,25281,26569,27225,27889,30625

%N Perfect squares which are neither the sum nor the difference of two primes.

%F A106547 with 0's removed.

%e a(2)=289 because it is the second perfect square which is impossible to obtain adding a prime to - or subtracting from - another one. 64 is not in the sequence because 64=67-3, a difference of two primes.

%Y Cf. A106544-A106548, A106562-A106564, A106571, A106574, A106575, A106577.

%K easy,nonn

%O 1,1

%A _Alexandre Wajnberg_, May 09 2005

%E Corrected and extended by _Ray Chandler_, May 12 2005