540609741211domain: NAppears in sequencesa(n) = (15^n - (-1)^n)/16.at n=11A239284Semiprimes of the form m^10 - m^9 + m^8 - m^7 + m^6 - m^5 + m^4 - m^3 + m^2 - m + 1.at n=5A245483a(n) = Sum_{j=0..10} (-n)^j.at n=15A269486