Triangle G(n,k) read by rows: number of order-preserving partial transformations (of an n-element totally ordered set) of waist k (waist(alpha) = max(Im(alpha))).

A111516

Triangle G(n,k) read by rows: number of order-preserving partial transformations (of an n-element totally ordered set) of waist k (waist(alpha) = max(Im(alpha))).

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =4a(6) =1a(7) =7a(8) =12a(9) =18a(10) =1a(11) =15a(12) =32a(13) =56a(14) =88a(15) =1a(16) =31a(17) =80a(18) =160a(19) =280a(20) =450a(21) =1a(22) =63a(23) =192a(24) =432a(25) =832a(26) =1452a(27) =2364a(28) =1a(29) =127

External references