Triangle read by rows: T(n, k) = t(n-k, k), where t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), and f(n) = 3*n + 3.
A257620
Triangle read by rows: T(n, k) = t(n-k, k), where t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), and f(n) = 3*n + 3.
Terms
- a(0) =1a(1) =3a(2) =3a(3) =9a(4) =36a(5) =9a(6) =27a(7) =297a(8) =297a(9) =27a(10) =81a(11) =2106a(12) =5346a(13) =2106a(14) =81a(15) =243a(16) =13851a(17) =73386a(18) =73386a(19) =13851a(20) =243a(21) =729a(22) =87480a(23) =868239a(24) =1761264a(25) =868239a(26) =87480a(27) =729a(28) =2187a(29) =540189
External references
- oeis: A257620