Limiting values of A136564.

Terms

a(0) =1a(1) =4a(2) =22a(3) =111a(4) =570a(5) =2917a(6) =15112a(7) =78900a(8) =416525a(9) =2221529a(10) =11974498a(11) =65211746a(12) =358742016a(13) =1992975905a(14) =11178149883a(15) =63279615534a(16) =361464920864