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 A162666 #17 Sep 08 2022 08:45:46 %S A162666 1,10,102,1060,11204,120200,1306008,14340560,158822416,1771073440, %T A162666 19856872032,223572243520,2525471411264,28599348360320, %U A162666 324490768902528,3687079238739200,41941489422336256,477496023050283520 %N A162666 a(n) = 20*a(n-1) - 98*a(n-2) for n > 1; a(0) = 1, a(1) = 10. %C A162666 Binomial transform of A147960. Tenth binomial transform of A077957. %H A162666 G. C. Greubel, <a href="/A162666/b162666.txt">Table of n, a(n) for n = 0..940</a> %H A162666 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (20,-98). %F A162666 a(n) = ((10+sqrt(2))^n + (10-sqrt(2))^n)/2. %F A162666 G.f.: (1-10*x)/(1-20*x+98*x^2). %F A162666 E.g.f.: exp(10*x)*cosh(sqrt(2)*x). - _Ilya Gutkovskiy_, Aug 11 2017 %p A162666 seq(coeff(series((1-10*x)/(1-20*x+98*x^2), x, n+1), x, n), n = 0..20); # _G. C. Greubel_, Aug 27 2019 %t A162666 Union[Flatten[NestList[{#[[2]],20#[[2]]-98#[[1]]}&,{1,10},20]]] (* _Harvey P. Dale_, Feb 25 2011 *) %t A162666 LinearRecurrence[{20,-98}, {1,10}, 20] (* _G. C. Greubel_, Aug 27 2019 *) %o A162666 (Magma) [ n le 2 select 9*n-8 else 20*Self(n-1)-98*Self(n-2): n in [1..18] ]; %o A162666 (PARI) my(x='x+O('x^20)); Vec((1-10*x)/(1-20*x+98*x^2)) \\ _G. C. Greubel_, Aug 27 2019 %o A162666 (Sage) %o A162666 def A162666_list(prec): %o A162666 P.<x> = PowerSeriesRing(ZZ, prec) %o A162666 return P((1-10*x)/(1-20*x+98*x^2)).list() %o A162666 A162666_list(20) # _G. C. Greubel_, Aug 27 2019 %o A162666 (GAP) a:=[1,10];; for n in [3..20] do a[n]:=20*a[n-1]-98*a[n-2]; od; a; # _G. C. Greubel_, Aug 27 2019 %Y A162666 Cf. A147960, A077957. %K A162666 nonn,easy %O A162666 0,2 %A A162666 _Klaus Brockhaus_, Jul 20 2009