Shifts left 2 places under Stirling2 transform.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =5a(5) =16a(6) =66a(7) =343a(8) =2167a(9) =16193a(10) =140919a(11) =1414947a(12) =16258868a(13) =211935996a(14) =3105828560a(15) =50748310068a(16) =918138961643