A378716 Triangle read by rows: T(n,k) is the number of k-Fibonacci polyominoes with an area of n, with k > 1.
1, 1, 1, 1, 0, 1, 2, 1, 0, 1, 2, 2, 0, 0, 1, 3, 0, 1, 0, 0, 1, 4, 2, 1, 0, 0, 0, 1, 5, 3, 1, 1, 0, 0, 0, 1, 7, 1, 1, 1, 0, 0, 0, 0, 1, 9, 5, 2, 0, 1, 0, 0, 0, 0, 1, 12, 5, 1, 1, 1, 0, 0, 0, 0, 0, 1, 16, 3, 2, 0, 0, 1, 0, 0, 0, 0, 0, 1, 21, 10, 3, 3, 0, 1, 0, 0, 0, 0, 0, 0, 1
Offset: 3
Examples
The triangle begins as: 1; 1, 1; 1, 0, 1; 2, 1, 0, 1; 2, 2, 0, 0, 1; 3, 0, 1, 0, 0, 1; 4, 2, 1, 0, 0, 0, 1; 5, 3, 1, 1, 0, 0, 0, 1; 7, 1, 1, 1, 0, 0, 0, 0, 1; 9, 5, 2, 0, 1, 0, 0, 0, 0, 1; 12, 5, 1, 1, 1, 0, 0, 0, 0, 0, 1; ...
Links
- Juan F. Pulido, José L. Ramírez, and Andrés R. Vindas-Meléndez, Generating Trees and Fibonacci Polyominoes, arXiv:2411.17812 [math.CO], 2024. See page 9.
Programs
-
Mathematica
T[n_, k_]:=SeriesCoefficient[1/(1-Sum[x^((k+i)(k-i+1)/2), {i, k}]), {x, 0, n}]; Table[T[n, k], {n, 2, 14}, {k, 2,n}]//Flatten
Formula
T(n, k) = [x^n] 1/(1 - Sum_{i=1..k} x^((k+i)*(k-i+1)/2) ).