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 A093969 #9 Sep 08 2019 01:24:50 %S A093969 0,1,0,3,8,25,72,203,560,1521,4080,10835,28536,74633,194040,501915, %T A093969 1292512,3315425,8474976,21597091,54884200,139127289,351877416, %U A093969 888121195,2237336592,5626467025,14126832720,35416929267,88670846936 %N A093969 a(n) = n*Pell(n-2). %C A093969 The signed version (-1)^(n+1)*n*Pell(n-2) is the second inverse binomial transform of A093967. %H A093969 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-2,-4,-1). %F A093969 G.f.: x(1-4x+5x^2)/(1-2x-x^2)^2; %F A093969 a(n) = n*(1 + sqrt(2))^n*(3*sqrt(2)/4 - 1) - n*(1 - sqrt(2))^n*(3*sqrt(2)/4 + 1). %Y A093969 Cf. A000129. %K A093969 easy,nonn %O A093969 0,4 %A A093969 _Paul Barry_, Apr 21 2004