10077690domain: NAppears in sequencesNumber of primitive (aperiodic) palindromes using a maximum of six different symbols.at n=16A056462Number of primitive (period n) periodic palindromes using a maximum of six different symbols.at n=16A056497a(n) = 6^n - 6.at n=8A178672a(n) = n^9 - n.at n=6A196289