-6960

Appears in sequences

• Site percolation series for 4.8 (bathroom tile) lattice.at n=34A120557
• Triangle t(n,m)=A039757(n,m)+A039757(n,n-m) read by rows.at n=24A155719
• a(1) = 1; a(n) = -Sum_{d|n, d < n} d * a(d).at n=47A342403