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 A329819 #18 Nov 22 2019 05:27:29 %S A329819 1,1,0,1,1,6,26,6,1,1,24,195,264,195,24,1,1,60,898,3276,5646,3276,898, %T A329819 60,1,1,120,3065,22260,72730,101520,72730,22260,3065,120,1,1,210,8526, %U A329819 105690,581475,1510860,2103740,1510860,581475,105690,8526,210,1 %N A329819 Triangular array, read by rows: T(n,k) = [(x*y*z)^k] (-1 + (1 + x + 1/x)*(1 + y + 1/y)*(1 + z + 1/z))^n for -n <= k <= n. %H A329819 Seiichi Manyama, <a href="/A329819/b329819.txt">Rows n = 0..25, flattened</a> %F A329819 T(n,k) = T(n,-k). %e A329819 Triangle begins: %e A329819 1; %e A329819 1, 0, 1; %e A329819 1, 6, 26, 6, 1; %e A329819 1, 24, 195, 264, 195, 24, 1; %e A329819 1, 60, 898, 3276, 5646, 3276, 898, 60, 1; %e A329819 1, 120, 3065, 22260, 72730, 101520, 72730, 22260, 3065, 120, 1; %o A329819 (PARI) {T(n, k) = polcoef(polcoef(polcoef((-1+(1+x+1/x)*(1+y+1/y)*(1+z+1/z))^n, k), k), k)} %Y A329819 T(n,0) gives A328874. %Y A329819 Cf. A260492, A329816, A329820. %K A329819 nonn,tabf %O A329819 0,6 %A A329819 _Seiichi Manyama_, Nov 21 2019