Triangle read by rows: T(n,k) = A(k,n-k), 1 <= k < n, 2 <= n, where A(m,n) is the number of distinct strings consisting of one X, 2*m-1 Y's and 2*n-1 Z's in which the X lies to the right of at least m Y's and at least n Z's.
A351583
Triangle read by rows: T(n,k) = A(k,n-k), 1 <= k < n, 2 <= n, where A(m,n) is the number of distinct strings consisting of one X, 2*m-1 Y's and 2*n-1 Z's in which the X lies to the right of at least m Y's and at least n Z's.
Terms
- a(0) =2a(1) =7a(2) =7a(3) =15a(4) =52a(5) =15a(6) =26a(7) =192a(8) =192a(9) =26a(10) =40a(11) =510a(12) =1086a(13) =510a(14) =40a(15) =57a(16) =1115a(17) =4098a(18) =4098a(19) =1115a(20) =57a(21) =77a(22) =2142a(23) =12075a(24) =20840a(25) =12075a(26) =2142a(27) =77a(28) =100a(29) =3752
External references
- oeis: A351583