1056731domain: NAppears in sequencesa(n) = (1/2)*A050871 (row sums of array T in A050870, periodic binary words).at n=21A050872Number of compositions (ordered partitions) of n where the gcd of the part sizes is not 1.at n=41A178472Number of compositions of n where any two parts have a common divisor > 1.at n=42A337667