4008960domain: NAppears in sequencesPartition the j digits of n into blocks of k, with 1 <= k <= j-1, starting at right and multiply. Sum of these numbers equals n.at n=30A275170Fourier coefficients of Eisenstein series of degree 2 and weight 4: a(n) = coefficient of the matrix [n, 0; 0, 1] with determinant n.at n=6A323991