A147856 Positive integers n such that n^2 = (x^4 - y^4)*(z^4 - t^4) where x>y and z>t are distinct pairs of integers with gcd(x,y)=gcd(z,t)=1.

520, 975, 2040, 3567, 7215, 7800, 9840, 13920, 19680, 30160, 40545, 53040, 57720, 62985, 95120, 108225, 138040, 151320, 180960, 230880, 247520, 286200, 289952, 352495, 473280, 535353, 546975, 720945, 769600, 1048560, 1141920, 1210560

Offset: 1

Author

Max Alekseyev, Nov 18 2008

Keywords

• nonn

Comments

Positive integers n such that n^2 = A147858(m)*A147858(k) for positive integers kA147854: any element n of A147854 is of the form a(k)*s^2 for some positive integer s.

4*A196289(2*k) and A196289(2*k+1) belong to this sequence.