2181023

Appears in sequences

• Number of nondecreasing arrangements of n+3 numbers in 0..8 with each number being the sum mod 9 of three others.at n=15A183903
• Number of (n+1) X 3 0..1 arrays with the permanents of 2 X 2 subblocks nondecreasing rightwards and downwards.at n=7A204717
• G.f.: Sum_{n>=1} x^n * (1+x)^n / (1-x^n).at n=30A227635