1,1

If A=[A157857] 3600*n.^2-n (3599, 14398, 32397,.,); Y=[A157858] 1728000*n -240 (1727760, 3455760..,); X=[A157859] 103680000*n^2-28800*n +1 (103651201, 414662401,.,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 103651201^2-3599 *1727760^2=1; 414662401^2-14398*3455760^2=1.

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

Edward Everett Withford, Pell Equation

Wolfram MathWorld, Pell Equation

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

For n=1, a(1)=103651201; n=2, a(2)=414662401

Cf. A157857, A157858

Sequence in context: A073643 A112717 A114679 this_sequence A157863 A035498 A018897

Adjacent sequences: A157856 A157857 A157858 this_sequence A157860 A157861 A157862

nonn

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