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 A377883 #10 Nov 11 2024 05:50:57 %S A377883 1,1,1,7,34,126,496,2052,8264,32776,130816,524272,2098144,8388576, %T A377883 33550336,134217792,536887424,2147483776,8589869056,34359738112, %U A377883 137439215104,549755813376,2199022206976,8796093023232,35184376285184,140737488357376,562949936644096 %N A377883 Cogrowth sequence of the 16-element modular group M4(2) = <S,T | S^8, T^2, STS^3T>. %C A377883 Gives the even terms, all the odd terms are 0. %C A377883 Also called M16, C4.C4. Gap identifier 16,6. %H A377883 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (6,-14,32,-40,32). %F A377883 G.f.: (4*x^5-14*x^4+17*x^3-9*x^2+5*x-1) / ((4*x-1) * (4*x^2+1) * (2*x^2-2*x+1)). %Y A377883 Cf. A007582 (D8), A377840 (C8 X C2), A377855 (C4:C4), A377885 (SD16). %K A377883 nonn,easy %O A377883 0,4 %A A377883 _Sean A. Irvine_, Nov 10 2024