a(n) = Sum_{k=0..n} Stirling2(n,k)^2.
A047797
a(n) = Sum_{k=0..n} Stirling2(n,k)^2.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =11a(4) =87a(5) =952a(6) =13513a(7) =237113a(8) =5016728a(9) =125121009a(10) =3615047527a(11) =119384499720
External references
- oeis: A047797