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 A157796 27225n^2 - 12098n + 1344. 3
 16471, 86048, 210075, 388552, 621479, 908856, 1250683, 1646960, 2097687, 2602864, 3162491, 3776568, 4445095, 5168072, 5945499, 6777376, 7663703, 8604480, 9599707, 10649384, 11753511, 12912088, 14125115, 15392592, 16714519 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The identity(1482401250*n^2-658736100*n+73180801)^2-(27225*n^2-12098*n+1344)*(8984250*n-1996170)^2=1 can be written as A157798(n)^2-a(n)*A157797(n)^2=1. LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..10000 Vincenzo Librandi, X^2-AY^2=1 Index entries for linear recurrences with constant coefficients, signature (3,-3,1). FORMULA G.f.: x*(-16471-36635*x-1344*x^2)/(x-1)^3. a(1)=16471, a(2)=86048, a(3)=210075, a(n)=3*a(n-1)-3*a(n-2)+a(n-3). - Harvey P. Dale, Jul 02 2011 MATHEMATICA Table[27225n^2-12098n+1344, {n, 25}]  (* Harvey P. Dale, Feb 20 2011 *) LinearRecurrence[{3, -3, 1}, {16471, 86048, 210075}, 25] (* Harvey P. Dale, Jul 02 2011 *) PROG (MAGMA) I:=[16471, 86048, 210075]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]]; (PARI) a(n)=27225*n^2-12098*n+1344 CROSSREFS Cf. A157797, A157798. Sequence in context: A283027 A031829 A057680 * A186848 A211841 A234054 Adjacent sequences:  A157793 A157794 A157795 * A157797 A157798 A157799 KEYWORD nonn,easy AUTHOR Vincenzo Librandi, Mar 07 2009 EXTENSIONS Edited by M. F. Hasler, Oct 08 2014 STATUS approved

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