a(n) = n! * {1 + Sum[i=1..n, 1/i*Sum(j=0..i-1, 1/j!)]}.
A093345
a(n) = n! * {1 + Sum[i=1..n, 1/i*Sum(j=0..i-1, 1/j!)]}.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =23a(4) =108a(5) =605a(6) =3956a(7) =29649a(8) =250892a(9) =2367629a(10) =24662700a(11) =281153801a(12) =3482350724a(13) =46572620757a(14) =668943488084
External references
- oeis: A093345