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 A115284 #6 Jan 22 2025 05:22:58
%S A115284 1,3,3,4,10,4,4,15,15,4,4,16,26,16,4,4,16,31,31,16,4,4,16,32,42,32,16,
%T A115284 4,4,16,32,47,47,32,16,4,4,16,32,48,58,48,32,16,4,4,16,32,48,63,63,48,
%U A115284 32,16,4,4,16,32,48,64,74,64,48,32,16,4
%N A115284 Correlation triangle of 4-C(1,n)-2*C(0,n) (A113311).
%C A115284 Row sums are the coordination sequence for cubic lattice A005899. Diagonal sums are A115285. T(2n,n) is A113770. T(2n,n)-T(2n,n+1) is 1,6,10,10,10,.... (10-4C(1,n)-5C(0,n)).
%F A115284 G.f.: (1+x)^2*(1+x*y)^2/((1-x)*(1-x*y)*(1-x^2*y)).
%F A115284 T(n, k) = Sum_{j=0..n} [j<=k]*(4-C(1, k-j)-2*C(0, k-j))*[j<=n-k]*(4-C(1, n-k-j)-2*C(0, n-k-j)).
%e A115284 Triangle begins:
%e A115284 1;
%e A115284 3, 3;
%e A115284 4, 10, 4;
%e A115284 4, 15, 15, 4;
%e A115284 4, 16, 26, 16, 4;
%e A115284 4, 16, 31, 31, 16, 4;
%e A115284 4, 16, 32, 42, 32, 16, 4;
%K A115284 easy,nonn,tabl
%O A115284 0,2
%A A115284 _Paul Barry_, Jan 19 2006