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 A113282 #5 Oct 18 2020 07:09:14 %S A113282 1,5,7,17,41,101,239,577,1393,3365,8119,19601,47321,114245,275807, %T A113282 665857,1607521,3880901,9369319,22619537,54608393,131836325,318281039, %U A113282 768398401,1855077841,4478554085,10812186007,26102926097,63018038201 %N A113282 Logarithmic derivative of the g.f. of A113281. %F A113282 G.f.: (1+x^2)/(1-x^2)/(1-2*x-x^2) + x*(3+x^2)/(1-x^4). a(2*n) = A113224(2*n), a(4*n+1) = 3 + A113224(4*n+1), a(4*n+3) = 1 + A113224(4*n+3), where A113224 is the self-convolution of A113281. %F A113282 a(n) ~ (1 + sqrt(2))^(n+1) / 2. - _Vaclav Kotesovec_, Oct 18 2020 %o A113282 (PARI) {a(n)=local(x=X+X*O(X^n)); polcoeff((1+x^2)/(1-x^2)/(1-2*x-x^2) + x*(3+x^2)/(1-x^4),n,X)} %Y A113282 Cf. A113281, A113283, A113284. %K A113282 nonn %O A113282 0,2 %A A113282 _Paul D. Hanna_, Oct 22 2005