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 A191657 #7 Mar 30 2012 18:40:59 %S A191657 1,1,-2,1,-2,32,1,-1,2,32,-272,1,-1,2,16,-64,-272,15872,1,-1,1,-4,16, %T A191657 -64,512,-136,544,15872,-707584,1,-1,1,-4,4,-32,64,512,-136,544,-8704, %U A191657 7936,-31744,-707584,89473024 %N A191657 Table, by rows, of numerators of alpha-coefficients in the symmetrized product of 2n Dirac matrices with two Tensor indices. %C A191657 The number of columns equals the number of partitions of the row index n. %C A191657 The denominators are A191658. From table 1 by Izaurieta et al. %H A191657 Fernando Izaurieta, Ricardo RamÃrez, Eduardo RodrÃguez, <a href="http://arxiv.org/abs/1106.1648">An efficient algorithm for the computation of the trace of the symmetrized product of an arbitrary number of Dirac matrices with two indices</a>, arXiv:1106.1648, June 08 2011. %e A191657 The coefficients corresponding to each partition of 4 are: %e A191657 1 + 1 + 1 + 1 -> 1/24; %e A191657 2 + 1 + 1 -> -1/3; %e A191657 2 + 2 -> 2/9; %e A191657 3 + 1 -> 32/45; %e A191657 4 -> -272/315. %Y A191657 Cf. A191658. %K A191657 sign,frac,tabf %O A191657 1,3 %A A191657 _Jonathan Vos Post_, Jun 10 2011