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 A377943 #14 Nov 14 2024 21:19:00 %S A377943 1,1,11,91,821,7381,66431,597871,5380841,48427561,435848051, %T A377943 3922632451,35303692061,317733228541,2859599056871,25736391511831, %U A377943 231627523606481,2084647712458321,18761829412124891,168856464709124011,1519708182382116101,13677373641439044901 %N A377943 Cogrowth sequence of the 16-element Pauli group C4 o D4 = <S,T,U | s^4, T^2, U^2, S^2(TU)^2, [S,T], [S,U]>. %C A377943 Gives the even terms, all the odd terms are 0. %H A377943 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (9, 1, -9). %F A377943 G.f.: (x^2-8*x+1) / ((x-1) * (9*x-1) * (x+1)). %Y A377943 Cf. A070775 (C4 X C4), A377855 (C4:C4), A047854 (D4 X C2). %K A377943 nonn,easy %O A377943 0,3 %A A377943 _Sean A. Irvine_, Nov 11 2024