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%I #13 Mar 17 2016 05:59:23
%S 3,48,813,4697,5694,6752,13773,25477,34989,125632,233328,362313,
%T 605634,673464,691659,941896,3654841,3952803,5024551,5619712,6509427,
%U 10833183,12473149
%N Integers n such that 1^2 + 3^2 + 5^2 + ... + (2*n-1)^2 = x^3 + y^3 has a solution in positive integers x and y.
%C Integers n such that n*(4*n^2 - 1)/3 is the sum of 2 positive cubes.
%e 3 is a term because 1^2 + 3^2 + 5^2 = 2^3 + 3^3.
%e 48 is a term because 1^2 + 3^2 + 5^2 + ... + 95^2 = 31^3 + 49^3.
%o (PARI) isA003325(n) = for(k=1, sqrtnint(n\2, 3), ispower(n-k^3, 3) && return(1));
%o a000447(n) = n*(4*n^2 - 1)/3;
%o for(n=1, 1e5, if(isA003325(a000447(n)), print1(n, ", ")));
%Y Cf. A000447, A003325, A269842.
%K nonn,more
%O 1,1
%A _Altug Alkan_, Mar 08 2016
%E a(10)-a(23) from _Chai Wah Wu_, Mar 16 2016
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