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 A178781 #18 Aug 28 2022 08:24:18 %S A178781 -1,1,0,1,0,0,0,-1,-1,0,-1,0,1,0,2,0,1,0,0,-1,0,-2,0,-1,0,1,0,1,1,0,0, %T A178781 0,-1,0,-1,1 %N A178781 Expansion of the polynomial (x^9-1)*(x^7-1)*(x^6-1)*(x^5-1)*(x^4-1)*(x^3-1)*(x-1) in increasing powers of x. %C A178781 q^63*(q^18-1)*(q^14-1)*(q^12-1)*(q^10-1)*(q^8-1)*(q^6-1)*(q^2-1) is the order of the simple group E_7(q), if q is a prime power. %C A178781 The x-polynomial f(x) and the q-polynomial g(q) are such that g(q) = q^63*f(q^2) - _Jean-François Alcover_, Aug 25 2022 %D A178781 R. L. Griess, Jr., Twelve Sporadic Groups, Springer, 1998; see p. 169. %o A178781 (PARI) Vecrev((x^9-1)*(x^7-1)*(x^6-1)*(x^5-1)*(x^4-1)*(x^3-1)*(x-1)) \\ _Michel Marcus_, Aug 25 2022 %Y A178781 Cf. A008869, A178795. %K A178781 sign,fini,full,easy %O A178781 0,15 %A A178781 _N. J. A. Sloane_, Dec 26 2010