1320352

Appears in sequences

• a(n) = phi(2^n - 1)/2.at n=20A056742
• G.f.: 16th root of weight enumerator of [32,31,2] Reed-Muller code RM(4,5).at n=3A110848
• a(n) = A000010(A001045(n)).at n=21A366773