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 A368435 #4 Dec 30 2023 23:41:33 %S A368435 1,2,4,2,2,4,10,8,3,2,4,8,16,18,12,4,2,4,8,12,24,28,26,16,5,2,4,8,12, %T A368435 18,32,40,40,34,20,6,2,4,8,12,18,24,42,52,56,52,42,24,7,2,4,8,12,18, %U A368435 24,32,52,66,72,72,64,50,28,8,2,4,8,12,18,24,32,40 %N A368435 Irregular triangular array T, read by rows: T(n,k) = number of sums |x-y|+|y-z| = 2n-2-k, where x,y,z are in {0,1,...,n}. %C A368435 Row n consists of 2n-1 positive integers having sum A000575(n) = n^3. %e A368435 First eight rows: %e A368435 1 %e A368435 2 4 2 %e A368435 2 4 10 8 3 %e A368435 2 4 8 16 18 12 4 %e A368435 2 4 8 12 24 28 26 16 5 %e A368435 2 4 8 12 18 32 40 40 34 20 6 %e A368435 2 4 8 12 18 24 42 52 56 52 42 24 7 %e A368435 2 4 8 12 18 24 32 52 66 72 72 64 50 28 8 %t A368435 t[n_] := t[n] = Tuples[Range[n], 3]; %t A368435 a[n_, k_] := Select[t[n], Abs[#[[1]] - #[[2]]] + Abs[#[[2]] - #[[3]]] == 2n-2-k &]; %t A368435 u = Table[Length[a[n, k]], {n, 1, 15}, {k, 0, 2 n - 2}]; %t A368435 Flatten[u] (* sequence *) %t A368435 Column[u] (* array *) %Y A368435 Cf. A000575, A007590 (limiting row), A368434, A368437. %K A368435 nonn,tabf %O A368435 1,2 %A A368435 _Clark Kimberling_, Dec 25 2023