66790domain: NAppears in sequencesa(2*n+1) = 9*a(n), a(2*n+2) = 10*a(n) + a(n-1).at n=32A116555a(n) = a(n-1) + a(n-2) + a(n-3), with a(0) = 1, a(1) = a(2) = 6.at n=17A214828Number of primes of the form (x+1)^7 - x^7 with x <= 10^n.at n=6A221980