A041473 - OEIS

%I #15 Sep 08 2022 08:44:54

%S 1,1,7,8,247,255,1777,2032,62737,64769,451351,516120,15934951,

%T 16451071,114641377,131092448,4047414817,4178507265,29118458407,

%U 33296965672,1028027428567,1061324394239,7395973794001,8457298188240,261114919441201,269572217629441

%N Denominators of continued fraction convergents to sqrt(252).

%H Vincenzo Librandi, <a href="/A041473/b041473.txt">Table of n, a(n) for n = 0..200</a>

%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,254,0,0,0,-1).

%F G.f.: -(x^2-x-1)*(x^4+8*x^2+1) / ((x^4-16*x^2+1)*(x^4+16*x^2+1)). - _Colin Barker_, Nov 18 2013

%F a(n) = 254*a(n-4) - a(n-8) for n>7. - _Vincenzo Librandi_, Dec 18 2013

%t Denominator[Convergents[Sqrt[252], 30]] (* _Vincenzo Librandi_, Dec 18 2013 *)

%o (Magma) I:=[1,1,7,8,247,255,1777,2032]; [n le 8 select I[n] else 254*Self(n-4)-Self(n-8): n in [1..40]]; // _Vincenzo Librandi_, Dec 18 2013

%Y Cf. A041472, A040236.

%K nonn,frac,easy

%O 0,3

%A _N. J. A. Sloane_.

%E More terms from _Colin Barker_, Nov 18 2013