375326930089domain: NAppears in sequencesa(0) = 1, a(1) = 5, a(n) = 4*a(n-1) - a(n-2).at n=20A001834a(n) = MPR2(n, 4), where MPR2(n, x) is the (monic) minimal polynomial of 2*cos(2*Pi/n) as defined in A232624.at n=40A309040