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 A140815 #21 Feb 26 2018 04:19:04 %S A140815 -1,0,-1,2,1,-3,3,1,-2,2,1,-5,10,-10,5,1,-1,1,1,-7,21,-35,35,-21,7,1, %T A140815 -4,6,-4,2,1,-6,15,-21,18,-9,3,1,-3,4,-2,1,1,-11,55,-165,330,-462,462, %U A140815 -330,165,-55,11,1,-4,5,-2,1,1,-13,78,-286,715,-1287,1716,-1716,1287,-715,286,-78,13,1,-5,11,-13,9,-3,1,1,-7,21 %N A140815 Irregular triangle read by rows: the n-th row gives the coefficients of Phi(n, 1-x), where Phi(n, x) is the n-th cyclotomic polynomial. %F A140815 t(n,m) = Coefficients(Cyclotomic(n,1-x)). %o A140815 (PARI) row(n)=Vec(polcyclo(n,1-x)); \\ _Joerg Arndt_, Feb 26 2018 %Y A140815 Cf. A136093, A136247. %K A140815 tabf,sign,easy,less %O A140815 1,4 %A A140815 _Roger L. Bagula_ and _Gary W. Adamson_, Jul 16 2008 %E A140815 Corrected and edited by _Joerg Arndt_, Feb 26 2018