89434106370domain: NAppears in sequencesGeneralized Euler number c(9,n).at n=4A064070Main diagonal of A349271.at n=8A349263Generalized Euler numbers, a(n) = n!*[x^n](sec(9*x)*(4*sin(3*x) + 2)*cos(3*x)^2).at n=8A349268