A377943 - OEIS

%I #14 Nov 14 2024 21:19:00

%S 1,1,11,91,821,7381,66431,597871,5380841,48427561,435848051,

%T 3922632451,35303692061,317733228541,2859599056871,25736391511831,

%U 231627523606481,2084647712458321,18761829412124891,168856464709124011,1519708182382116101,13677373641439044901

%N 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 Gives the even terms, all the odd terms are 0.

%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (9, 1, -9).

%F G.f.: (x^2-8*x+1) / ((x-1) * (9*x-1) * (x+1)).

%Y Cf. A070775 (C4 X C4), A377855 (C4:C4), A047854 (D4 X C2).

%K nonn,easy

%O 0,3

%A _Sean A. Irvine_, Nov 11 2024