19978245

Appears in sequences

• a(n) = C(n+3,3)*n^3/4.at n=27A085284
• 3-parking triangle T(r, i, 3) read by rows: T(r, i, k) = (r + 1)^(i-1)*binomial(k*(r + 1) + r - i - 1, r - i) with k = 3 and 0 <= i <= r.at n=40A329059