a(n) = 2*n*a(n-1) - a(n-2), with a(0)=0, a(1)=1.
A106174
a(n) = 2*n*a(n-1) - a(n-2), with a(0)=0, a(1)=1.
Terms
- a(0) =0a(1) =1a(2) =4a(3) =23a(4) =180a(5) =1777a(6) =21144a(7) =294239a(8) =4686680a(9) =84066001a(10) =1676633340a(11) =36801867479a(12) =881568186156
External references
- oeis: A106174