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 A176625 #12 Sep 08 2022 08:45:53 %S A176625 1,1,1,1,-2,1,1,-5,-5,1,1,-8,-11,-8,1,1,-11,-17,-17,-11,1,1,-14,-23, %T A176625 -26,-23,-14,1,1,-17,-29,-35,-35,-29,-17,1,1,-20,-35,-44,-47,-44,-35, %U A176625 -20,1,1,-23,-41,-53,-59,-59,-53,-41,-23,1,1,-26,-47,-62,-71,-74,-71,-62,-47 %N A176625 T(n,k) = 1 + 3*k*(k - n), triangle read by rows (n >= 0, 0 <= k <= n). %F A176625 T(n,k) = 1 - A000326(n) + A000326(k) + A000326(n-k). %e A176625 Triangle begins: %e A176625 1; %e A176625 1, 1; %e A176625 1, -2, 1: %e A176625 1, -5, -5, 1; %e A176625 1, -8, -11, -8, 1; %e A176625 1, -11, -17, -17, -11, 1; %e A176625 1, -14, -23, -26, -23, -14, 1; %e A176625 1, -17, -29, -35, -35, -29, -17, 1; %e A176625 1, -20, -35, -44, -47, -44, -35, -20, 1; %e A176625 1, -23, -41, -53, -59, -59, -53, -41, -23, 1; %e A176625 1, -26, -47, -62, -71, -74, -71, -62, -47, -26, 1; %e A176625 ... %t A176625 a[n_] = n*(3*n - 1)/2; (* A000326 *) %t A176625 t[n_, m_] = 1 - a[n] + a[m] + a[n - m]; %t A176625 Table[Table[t[n, m], {m, 0, n}], {n, 0, 10}]; %t A176625 Flatten[%] %o A176625 (Maxima) create_list(1 + 3*k*(k - n), n, 0, 20, k, 0, n); /* _Franck Maminirina Ramaharo_, Nov 25 2018 */ %o A176625 (Magma) / * As triangle */ [[1 + 3*k*(k - n): k in [0..n]]: n in [0.. 15]]; // _Vincenzo Librandi_, Nov 26 2018 %Y A176625 Cf. A000326, A156070, A156072, A176305, A176306, A176307, A176339, A176344. %K A176625 sign,tabl,easy %O A176625 0,5 %A A176625 _Roger L. Bagula_, Apr 22 2010 %E A176625 Edited and name clarified by _Franck Maminirina Ramaharo_, Nov 25 2018