a(n) = exp(2) * Sum_{i>=0} Sum_{j>=0} (-1)^(i+j) * (i*j)^n / (i! * j!).
A337053
a(n) = exp(2) * Sum_{i>=0} Sum_{j>=0} (-1)^(i+j) * (i*j)^n / (i! * j!).
Terms
- a(0) =1a(1) =1a(2) =0a(3) =1a(4) =1a(5) =4a(6) =81a(7) =81a(8) =2500a(9) =71289a(10) =170569a(11) =4752400a(12) =314388361a(13) =2553584089a(14) =12138750976
External references
- oeis: A337053