a(n) = n!*sum( i+j<=n, 1/i!/j! ) for 0 <= i <= j < n.
A076176
a(n) = n!*sum( i+j<=n, 1/i!/j! ) for 0 <= i <= j < n.
Terms
- a(0) =1a(1) =2a(2) =7a(3) =25a(4) =111a(5) =571a(6) =3468a(7) =24340a(8) =194883a(9) =1754203a(10) =17542668a(11) =192970372a(12) =2315646974a(13) =30103414758a(14) =421447816520
External references
- oeis: A076176