A069117 Numbers n such that A068589(n) is a perfect square.

1, 2, 3, 4, 5, 9, 10, 11, 12, 13, 14, 15, 16, 17, 21, 22, 23, 27, 28, 29, 30, 31, 32, 63, 64, 65, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 105, 106, 107, 108, 109, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 189, 190, 191, 192, 193, 194, 195

Offset: 1

Author

Benoit Cloitre, Apr 07 2002

Keywords

• easy
• nonn

Programs

PARI

precision 1000 digits : for(n=1,300,if(sqrt(denominator(sum(i=1,n,1/i^3))/denominator(sum(i=1,n,1/i))) == floor(sqrt(denominator(sum(i=1,n,1/i^3))/denominator(sum(i=1,n,1/i)))),print1(n,",")))