Third right hand column (n-m=2) of the A156920 triangle.

A156922

Third right hand column (n-m=2) of the A156920 triangle.

Terms

    a(0) =1a(1) =15a(2) =129a(3) =877a(4) =5280a(5) =29658a(6) =159742a(7) =838038a(8) =4323003a(9) =22057825a(10) =111750519a(11) =563535483a(12) =2833221970a(13) =14216330916a(14) =71243079660a(15) =356731958812

External references