cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A116872 Subtriangle of generalized Catalan triangle CM(1,2) = A116880.

Original entry on oeis.org

1, 3, 7, 13, 29, 41, 67, 147, 195, 247, 381, 829, 1069, 1277, 1545, 2307, 4995, 6339, 7379, 8451, 9975, 14589, 31485, 39549, 45373, 50733, 56829, 66057, 95235, 205059, 255747, 290691, 320707, 351187, 388099
Offset: 1

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Author

Wolfdieter Lang, Mar 24 2006

Keywords

Comments

This triangle a(n,m) appears for the unnormalized one-point function T(n,n+m-1) in the totally asymmetric exclusion process (see A067323 for the references) for the (unphysical) values alpha=1, beta=2.

Crossrefs

Row sums give A116879.

Formula

a(n,m)=A116880(n,m-1), n>=m>=1.
G.f. for column m>=1: (x^m)*(-(C2(m) + ((2^2)/x^(m-1))*(c(m-1,2*x)-1)/(2*x)) + 2*(C2(m-1) + (2/x^(m-1))*c(m-2,2*x))*c(2*x))/(1+x) where C2(n):=A064062(n), c(m,x):=sum(C(k)*x^k,k=0..m) with C(k):=A000108(k) (Catalan numbers) and c(x) is the g.f. of A000108.