116601199

Appears in sequences

• a(0) = 0, a(1) = 1, a(2*n) = n*a(2*n-1) + a(2*n-2), a(2*n+1) = a(2*n) + a(2*n-1).at n=21A056921
• a(n) = n*a(n-1) - a(n-2), with a(-1) = 0, a(0) = 1.at n=13A058797
• a(n) = (n-1)*a(n-1)-a(n-2), a(0)=0, a(1)=1.at n=13A121965