47780

Appears in sequences

• a(1)=a(2)=1. a(n+1) = a(n) + a(largest prime dividing n).at n=44A128215
• Number of (n+1) X (5+1) 0..3 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).at n=12A235286