4194352

Appears in sequences

• Numbers k for which A019565(2k)-1 is a multiple of A000265(phi(A019565(2k))).at n=49A339973
• a(0) = 4; to obtain a(k), write out the base-(2^k) expansion of a(k-1), bump to base 2^(k+1), then subtract 1.at n=20A372237