139188domain: NAppears in sequencesIrregular triangle T(n,k) read by rows: The number of tilings of the n X n board by 1 X 1 and k 3 X 3 squares, n >= 0, k >= 0.at n=41A276171Numbers k such that Bernoulli number B_{k} has denominator 3404310.at n=22A295596