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 A292881 #18 Oct 31 2017 12:37:58 %S A292881 1,0,72,1440,54216,2134080,93993120,4423628160,219463602120, %T A292881 11341793393280 %N A292881 Number of n-step closed paths on the E6 lattice. %C A292881 Calculated by brute force computational enumeration. %C A292881 The moments of the imaginary part of the suitably normalized E6 lattice Green's function. %H A292881 S. Savitz and M. Bintz, <a href="https://arxiv.org/abs/1710.10260">Exceptional Lattice Green's Functions</a>, arXiv:1710.10260 [math-ph], 2017. %F A292881 Summed combinatorial expressions and recurrence relations for this sequence exist, but have not been determined. These would allow one to write a differential equation or hypergeometric expression for the E6 lattice Green's function. %e A292881 The 2-step walks consist of hopping to one of the 72 minimal vectors of the E6 lattice and then back to the origin. %Y A292881 Cf. A126869 (Linear A1 lattice), A002898 (Hexagonal A2), A002899 (FCC A3), A271432 (D4), A271650 (D5), A271651 (D6), A292882 (E7), A271670 (D7), A292883 (E8), A271671 (D8). %K A292881 nonn,walk,more %O A292881 0,3 %A A292881 _Samuel Savitz_, Sep 26 2017