68719476755domain: NAppears in sequencesTriangle T(n, k, q) = binomial(n, k) - 1 + q^(n*binomial(n-2, k-1)) with T(n, 0, q) = T(n, n, q) = 1 and q = 2, read by rows.at n=24A173043a(n) = Sum_{d|n} d * 4^(n/d-1).at n=18A359190