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 A178795 #20 Aug 28 2022 08:25:59 %S A178795 1,-1,0,0,-1,1,-1,0,1,-1,1,1,-2,3,-1,-1,3,-3,1,1,-4,3,-1,-3,4,-4,1,3, %T A178795 -5,4,0,-3,6,-3,0,4,-5,3,1,-4,4,-3,-1,3,-4,1,1,-3,3,-1,-1,3,-2,1,1,-1, %U A178795 1,0,-1,1,-1,0,0,-1,1 %N A178795 Expansion of the polynomial (x^15-1)*(x^12-1)*(x^10-1)*(x^9-1)*(x^7-1)*(x^6-1)*(x^4-1)*(x-1) in increasing powers of x. %C A178795 q^120*(q^30-1)*(q^24-1)*(q^20-1)*(q^18-1)*(q^14-1)*(q^12-1)*(q^8-1)*(q^2-1) is the order of the simple group E_8(q), if q is a prime power. %C A178795 If f(x) is the x-polynomial and g(q) the q-polynomial, then g(q) = q^120*f(q^2). - _Jean-François Alcover_, Aug 25 2022 %D A178795 R. L. Griess, Jr., Twelve Sporadic Groups, Springer, 1998; see p. 169. %H A178795 Wikipedia, <a href="https://en.wikipedia.org/wiki/E8_(mathematics)">Lie group E8</a> %e A178795 With p=2 one gets the order of E_8(2): 337804753143634806261388190614085595079991692242467651576160959909068800000. - _Jean-François Alcover_, Aug 25 2022 %o A178795 (PARI) Vec((x^15-1)*(x^12-1)*(x^10-1)*(x^9-1)*(x^7-1)*(x^6-1)*(x^4-1)*(x-1)) \\ _Michel Marcus_, Aug 25 2022 %Y A178795 Cf. A009968, A178779, A178780, A178781. %K A178795 sign,fini,full %O A178795 0,13 %A A178795 _N. J. A. Sloane_, Dec 26 2010