1,1

If A=[A157824] 3600*n.^2-6751*n +3165 (14, 4063, 15312,.,); Y=[A157825] 1728000*n - 1620240 (107760, 1835760..,); X=[A157826] 103680000*n^2-194428800*n +91152001 (403201, 117014401,.,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example:403201^2-14 *107760^2=1; 117014401^2-4063*1835760^2=1.

Edward Everett Withford, Pell Equation

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

Philippe Chevanne, Pell Equation

a(n)=103680000*n^2-194428800*n+91152001 (n>0)

For n=1, a(1)=403201; n=2, a(2)=117014401

Cf. A157824, A157825

Sequence in context: A015424 A083634 A096890 this_sequence A043609 A078519 A152869

Adjacent sequences: A157823 A157824 A157825 this_sequence A157827 A157828 A157829

nonn

Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 07 2009