295159215856domain: NAppears in sequencesAn 8th-degree product form sequence: a(n)=Product[(1 + 4*Sin[k*Pi/n]^2 + 16*Sin[k*Pi/n]^4 + 64*Sin[k*Pi/n]^6 + 256*Sin[k*Pi/n]^8), {k, 1, Floor[(n - 1)/2]}].at n=17A152144