This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A162757 #5 Jun 30 2023 00:53:09 %S A162757 1,7,51,381,2889,22095,169803,1308501,10098513,78001623,602768547, %T A162757 4659169005,36018666009,278471414943,2153041001019,16646935319109, %U A162757 128712870795681,995205584017575,7694942271953427,59497522990861149 %N A162757 a(n) = 12*a(n-1)-33*a(n-2) for n > 1; a(0) = 1, a(1) = 7. %C A162757 Sixth binomial transform of A108411. Binomial transform of A162558. Inverse binomial transform of A162758. %H A162757 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (12, -33). %F A162757 a(n) = ((3+sqrt(3))*(6+sqrt(3))^n+(3-sqrt(3))*(6-sqrt(3))^n)/6. %F A162757 G.f.: (1-5*x)/(1-12*x+33*x^2). %o A162757 (Magma) [ n le 2 select 6*n-5 else 12*Self(n-1)-33*Self(n-2): n in [1..20] ]; %Y A162757 Cf. A108411 (powers of 3 repeated), A162558, A162758. %K A162757 nonn %O A162757 0,2 %A A162757 _Klaus Brockhaus_, Jul 13 2009