a(n) = (-5*B(n+2) + (2*n+9)*B(n+1) + (2*n+1)*B(n))/4, where the B(i) are Bell numbers (A000110).
A226854
a(n) = (-5*B(n+2) + (2*n+9)*B(n+1) + (2*n+1)*B(n))/4, where the B(i) are Bell numbers (A000110).
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =11a(6) =89a(7) =660a(8) =4795a(9) =35067a(10) =261505a(11) =2001608a(12) =15777434a(13) =128270836a(14) =1076208942a(15) =9318227402a(16) =83230080505a(17) =766465520673
External references
- oeis: A226854