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 A292883 #12 Oct 31 2017 12:37:37 %S A292883 1,0,240,13440,1260720,137813760,17141798400,2336327078400, %T A292883 341350907713200 %N A292883 Number of n-step closed paths on the E8 lattice. %C A292883 Calculated by brute force computational enumeration. %C A292883 The moments of the imaginary part of the suitably normalized E8 lattice Green's function. %H A292883 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 A292883 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 E8 lattice Green's function. %e A292883 The 2-step walks consist of hopping to one of the 240 minimal vectors of the E8 lattice and then back to the origin. %Y A292883 Cf. A126869 (Linear A1 lattice), A002898 (Hexagonal A2), A002899 (FCC A3), A271432 (D4), A271650 (D5), A292881 (E6), A271651 (D6), A292882 (E7), A271670 (D7), A271671 (D8). %K A292883 nonn,walk,more %O A292883 0,3 %A A292883 _Samuel Savitz_, Sep 26 2017