1,1

If A=[A157853] 3600*n.^2-1601*n +178 (2177, 11376, 27775,.,); Y=[A157854] 1728000*n - 384240 (1343760, 3071760..,); X=[A157855] 103680000*n^2-46108800*n +5126401 (62697601, 327628801,.,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 62697601^2-2177 *1343760^2=1; 327628801^2-11376*3071760^2=1.

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

Edward Everett Withford, Pell Equation

Philippe Chevanne, Pell Equation

a(n)=103680000*n^2-46108800*n+5126401 (n>0)

For n=1, a(1)=62697601; n=2, a(2)=327628801

Cf. A157853, A157854

Sequence in context: A104931 A096559 A125063 this_sequence A017539 A116499 A164725

Adjacent sequences: A157852 A157853 A157854 this_sequence A157856 A157857 A157858

nonn

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