125449domain: NAppears in sequencesIrregular triangle read by rows: T(n,i) = number of n X n semi-canonical binary matrices with exactly i 1's, where 0 <= i <= n^2.at n=73A268523a(n) = coefficient of x^n in the power series A(x) such that: x = Sum_{n=-oo..+oo} (-1)^n * x^n * (3 + x^n)^n * A(x)^n.at n=8A359723