Triangle read by rows: T(n,k) = C(n) + C(k) - 1 where C(n) = A000108(n) are the Catalan numbers, 0 <= k <= n.

A131429

Triangle read by rows: T(n,k) = C(n) + C(k) - 1 where C(n) = A000108(n) are the Catalan numbers, 0 <= k <= n.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =3a(6) =5a(7) =5a(8) =6a(9) =9a(10) =14a(11) =14a(12) =15a(13) =18a(14) =27a(15) =42a(16) =42a(17) =43a(18) =46a(19) =55a(20) =83a(21) =132a(22) =132a(23) =133a(24) =136a(25) =145a(26) =173a(27) =263a(28) =429a(29) =429

External references