1514610

Appears in sequences

• a(n) = (2*(-1)^n - 2^(n+1) + 3*n*2^n)/9.at n=18A140960
• Triangular array read by rows. T(n,k) is the number of idempotent Boolean relation matrices with rank k, n >= 0, 0 <= k <= n.at n=25A363232