16936647121domain: NAppears in sequencesa(n) = n^8 - n^6 + n^4 - n^2 + 1.at n=19A060892Primes of the form sigma_4(k)/sigma_2(k), arising in A066109.at n=22A066110a(n) = sigma_4(n^4)/sigma_2(n^4).at n=18A077457Greatest prime factor of n^10+1.at n=18A240553