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%I #32 Sep 08 2022 08:45:41
%S 46,263,1538,3871,7262,11711,17218,23783,31406,40087,49826,60623,
%T 72478,85391,99362,114391,130478,147623,165826,185087,205406,226783,
%U 249218,272711,297262,322871,349538,377263,406046,435887,466786,498743,531758
%N 529n^2 - 312n + 46.
%C The identity (279841*n^2-165048*n+24335)^2-(529*n^2-312*n+46)*(12167*n-3588)^2=1 can be written as A156843(n)^2-a(n)*A156846(n)^2=1 for n>0.
%H Vincenzo Librandi, <a href="/A156841/b156841.txt">Table of n, a(n) for n = 0..10000</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F a(n) = 3*a(n-1) -3*a(n-2) +a(n-3).
%F G.f.: (46+125*x+887*x^2)/(1-x)^3.
%t LinearRecurrence[{3,-3,1},{46, 263, 1538},40]
%o (Magma) I:=[46, 263, 1538]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]];
%o (PARI) a(n)=529*n^2-312*n+46 \\ _Charles R Greathouse IV_, Dec 23 2011
%Y Cf. A156843, A156846, A156849.
%K nonn,easy
%O 0,1
%A _Vincenzo Librandi_, Feb 17 2009
%E Edited by _Charles R Greathouse IV_, Jul 25 2010
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