A115154 Triangle of numbers related to the generalized Catalan sequence C(3;n+1) = A064063(n+1), n>=0.
1, 1, 4, 1, 13, 25, 1, 40, 115, 190, 1, 121, 466, 1036, 1606, 1, 364, 1762, 4870, 9688, 14506, 1, 1093, 6379, 20989, 50053, 93571, 137089, 1, 3280, 22417, 85384, 235543, 516256, 927523, 1338790, 1, 9841, 77092, 333244, 1039873, 2588641, 5371210
Offset: 0
Examples
Triangle begins: 1; 1, 4; 1, 13, 25; 1, 40, 115, 190; 1, 121, 466, 1036, 1606; ... 466 = a(4,3) = a(4,2) + 3*a(3,3) = 121 + 3*115.
Links
- B. Derrida, E. Domany and D. Mukamel, An exact solution of a one-dimensional asymmetric exclusion model with open boundaries, J. Stat. Phys. 69, 1992, 667-687; eqs. (20), (21), p. 672.
- Wolfdieter Lang, First 10 rows.
Crossrefs
Row sums give A115187.
Formula
a(n,n+1)=A064063(n+1) (main diagonal with M=1); a(n,n-M+2)= a(n,n-M+1) + 3*a(n-1,n-M+2), M>=2; a(n,1)=1; n>=0.
G.f. for diagonal sequence M=1: GY(1,x):=(3*c(3*x)-1)/(2+x) with c(x) the o.g.f. of A000108 (Catalan); for M=2: GY(2,x)=(1-3*x)*GY(1,x)-1; for M>=3: GY(M,x)= GY(M-1,x) - 3*x*GY(M-2,x) + 2*x^(M-2).
Comments