10400574

Appears in sequences

• a(n) = Sum_{j = 1..n} Sum_{i = 1..n} (i + j)! / (i! * j!).at n=12A144657
• a(n) = Sum_{k=0..floor(n/2)} (C(n+2, k+2) - C(n+2, k)).at n=23A194124