1,1

If A=[A157861] 3600*n.^2+n (3601, 14402, 32403,.,); Y=[A157862] 1728000*n +240 (1728240, 3456240..,); X=[A157863] 103680000*n^2+28800*n +1 (103708801, 414777601,.,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 103708801^2-3601 *1728240^2=1; 414777601^2-14402*3456240^2=1.

Vincenzo Librandi, X^2-AY^2=1

Philippe Chevanne, Pell Equation

Edward Everett Withford, Pell Equation

a(n)=103680000*n^2+28800*n+1 (n>0)

For n=1, a(1)=103708801; n=2, a(2)=414777601

Cf. A157861, A157862

Sequence in context: A112717 A114679 A157859 this_sequence A035498 A018897 A124149

Adjacent sequences: A157860 A157861 A157862 this_sequence A157864 A157865 A157866

nonn

Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 08 2009