81206domain: NAppears in sequencesa(n) = 225*n^2 - n.at n=18A156813a(n) = 361*n^2 - 19.at n=14A158595Number of 3 X n 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 1 0 0 vertically.at n=9A207961Expansion of Product_{k>=1} (1+x^k)^k / (1-x^k).at n=18A262667