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 A162963 #7 Sep 08 2022 08:45:46 %S A162963 2,5,10,25,50,125,250,625,1250,3125,6250,15625,31250,78125,156250, %T A162963 390625,781250,1953125,3906250,9765625,19531250,48828125,97656250, %U A162963 244140625,488281250,1220703125,2441406250,6103515625,12207031250 %N A162963 a(n) = 5*a(n-2) for n > 2; a(1) = 2, a(2) = 5. %C A162963 Binomial transform is A162770, second binomial transform is A001077 without initial 1, third binomial transform is A162771, fourth binomial transform is A162772, fifth binomial transform is A162773. %H A162963 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (0,5). %F A162963 a(n) = (3-(-1)^n)*5^(1/4*(2*n-1+(-1)^n))/2. %F A162963 G.f.: x*(2+5*x)/(1-5*x^2). %F A162963 a(n) = A026383(n) for n >= 1. %o A162963 (Magma) [ n le 2 select 3*n-1 else 5*Self(n-2): n in [1..29] ]; %Y A162963 Cf. A000351 (powers of 5), A026383, A001077, A162770, A162771, A162772, A162773. %K A162963 nonn,easy %O A162963 1,1 %A A162963 _Klaus Brockhaus_, Jul 19 2009