a(n) is the number of integer sequences b(0..n) of length n+1, with 0 <= b(k) <= k! and monotonic b(k) <= b(k+1).
A355129
a(n) is the number of integer sequences b(0..n) of length n+1, with 0 <= b(k) <= k! and monotonic b(k) <= b(k+1).
Terms
- a(0) =2a(1) =3a(2) =7a(3) =40a(4) =856a(5) =91821a(6) =60080136a(7) =279276911843
External references
- oeis: A355129