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 A143255 #14 Aug 10 2025 10:33:22
%S A143255 1,-2,-1,-3,0,-1,0,0,0,0,-5,0,0,0,-1,6,3,2,0,0,1,-7,0,0,0,0,0,-1,0,0,
%T A143255 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,10,5,0,0,2,0,0,0,0,1,-11,0,0,0,0,0,0,0,
%U A143255 0,0,-1,0,0,0,0,0,0,0,0,0,0,0,0,-13,0,0,0,0,0,0,0,0,0,0,0,-1,14,7,0,0,0,0,2,0,0,0,0,0,0,1
%N A143255 Triangle read by rows, A128407 * A126988; 1<=k<=n.
%C A143255 Left border = A055615: (1, -2, -3, 0, -5, 6, -7,...).
%C A143255 Right border = A008683, mu(n).
%C A143255 Row sums = A063441: (1, -3, -4, 0, -6, 12, 8,...).
%F A143255 Triangle read by rows, A128407 * A126988; 1<=k<=n.
%F A143255 t(n,m) = MoebiusMu(n) * A126988(n,m); t(n,m) = MoebiusMu(n) * if(m == 1, n, if(n mod m == 0, n/m, 0)). - _Roger L. Bagula_, Sep 06 2008
%e A143255 Triangle begins:
%e A143255 1;
%e A143255 -2, -1;
%e A143255 -3, 0, -1;
%e A143255 0, 0, 0, 0;
%e A143255 -5, 0, 0, 0, -1;
%e A143255 6, 3, 2, 0, 0, 1;
%e A143255 -7, 0, 0, 0, 0, 0, -1;
%e A143255 0, 0, 0, 0, 0, 0, 0, 0;
%e A143255 0, 0, 0, 0, 0, 0, 0, 0, 0;
%e A143255 10, 5, 0, 0, 2, 0, 0, 0, 0, 1;
%e A143255 ...
%t A143255 t[n_, m_] = MoebiusMu[n]*If[m == 1, n, If[Mod[n, m] == 0, n/m, 0]]; Table[t[n, m], {n, 1, 14}, {m, 1, n}] // Flatten (* _Roger L. Bagula_, Sep 06 2008 *)
%Y A143255 Cf. A008683, A063441, A055615, A128407, A126988.
%Y A143255 Cf. A128988.
%K A143255 tabl,sign
%O A143255 1,2
%A A143255 _Gary W. Adamson_, Aug 02 2008