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 A162255 #12 May 26 2024 08:24:08
%S A162255 3,2,6,4,12,8,24,16,48,32,96,64,192,128,384,256,768,512,1536,1024,
%T A162255 3072,2048,6144,4096,12288,8192,24576,16384,49152,32768,98304,65536,
%U A162255 196608,131072,393216,262144,786432,524288,1572864,1048576,3145728,2097152
%N A162255 a(n) = 2*a(n-2) for n > 2; a(1) = 3, a(2) = 2.
%C A162255 Apparently a(n) = A074323(n+1). a(n) = A072946(n-1) for n > 1.
%C A162255 Partial sums are in A164053.
%C A162255 Binomial transform is A135532 without initial term -1. Second binomial transform is A161938.
%H A162255 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (0, 2).
%F A162255 a(n) = (2^(1/4))^(3+2*n+(-1)^n) * (2-(-1)^n)/2.
%F A162255 G.f.: x*(3+2*x)/(1-2*x^2).
%F A162255 E.g.f.: cosh(sqrt(2)*x) + 3*sinh(sqrt(2)*x)/sqrt(2) - 1. - _Stefano Spezia_, May 26 2024
%t A162255 LinearRecurrence[{0,2},{3,2},50] (* _Harvey P. Dale_, Aug 28 2012 *)
%o A162255 (PARI) m=42; u=concat([3, 2], vector(m-2)); for(n=3, m, u[n]=2*u[n-2]); u
%Y A162255 Cf. A074323, A072946, A164053, A135532, A161938.
%K A162255 nonn,easy
%O A162255 1,1
%A A162255 _Klaus Brockhaus_, Jun 29 2009
%E A162255 G.f. corrected, comments and cross-references added by _Klaus Brockhaus_, Aug 08 2009
%E A162255 Corrected by _Harvey P. Dale_, Aug 28 2012