70551domain: NAppears in sequencesa(n) = n*(n + 1)*(n^2 - 3*n + 5)/6.at n=26A006484Number of ternary search trees on n keys.at n=13A019497Expansion of 1/((1-3x)(1-4x)(1-7x)(1-11x)).at n=4A02804126-gonal pyramidal numbers: a(n) = n*(n+1)*(8*n-7)/2.at n=26A256646