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 A187163 #24 Mar 05 2022 22:11:27 %S A187163 0,24,108,288,600,1080,1764,2688,3888,5400,7260,9504,12168,15288, %T A187163 18900,23040,27744,33048,38988,45600,52920,60984,69828,79488,90000, %U A187163 101400,113724,127008,141288,156600,172980,190464,209088,228888,249900,272160 %N A187163 Number of 2-step self-avoiding walks on an n X n X n cube summed over all starting positions. %C A187163 Row 2 of A187162. %H A187163 R. H. Hardin, <a href="/A187163/b187163.txt">Table of n, a(n) for n = 1..50</a> %H A187163 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1). %F A187163 a(n) = 6*n^3 - 6*n^2. %F A187163 From _Colin Barker_, Apr 20 2018: (Start) %F A187163 G.f.: 12*x^2*(2 + x) / (1 - x)^4. %F A187163 a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>4. %F A187163 (End) %F A187163 a(n) = 12 * A006002(n-1). - _Alois P. Heinz_, Feb 28 2022 %e A187163 A solution for 2 X 2 X 2: %e A187163 0 0 0 0 %e A187163 1 0 2 0 %Y A187163 Cf. A006002, A187162. %K A187163 nonn,easy %O A187163 1,2 %A A187163 _R. H. Hardin_, Mar 06 2011