cp's OEIS Frontend

These are the entries of a triangle which starts

1,

1,

1, 2,

1, 3,

1, 4, 7,

1, 5, 12,

1, 6, 18, 29,...

The numbers d(i,n) in the row with index n are recursively defined for 0 <= n and 0 <= i <= n/2, by d(0,n) = 1 for all n, and d(i,n) = 2d(i-1,n-1) + d(i,n-1) - d(i-1,n-2) for 0 < i < n/2, and d(i,2i) = 3d(i-1,n-1) - d(i-1,n-2).

The numbers d(i,n-1) and d(i,n) form the dimension vector of the Fibonacci modules P(n), these are indecomposable quiver representations of the 3-regular tree with bipartite orientation.

A linear combination of the row n (with coefficients either 1 or of the form 3*2^t) gives a partition of the Fibonacci number f_{2n+2}, see A000045 and A001906.

The sequence A177011 is obtained by reading the rows with even index from the right.

The sequence A177020 is obtained by reading the rows with odd index from the right.

The sequence of the entries in the last column of the triangle, with even row index is recorded as A132262, the sequence of the entries in the last column of the triangle, with odd row index is A110122 (Number of Delannoy paths of length n with no EE's crossing the line y=x)

The sequence A197957 is obtained by taking differences of pairs of numbers in neighboring rows of the triangle.