390051domain: NAppears in sequencesa(n) = (concatenation in ascending order of divisors of 2^n)/2^n.at n=5A077352a(n) = A078218(n)/n.at n=31A078810Positive integers k such that (k+1)^4 has a divisor congruent to -1 modulo k.at n=57A350916a(0) = 3, a(1) = 3, and a(n) = 6*a(n-1) - a(n-2) - 4 for n >= 2.at n=8A350921