a(1) = a(2) = 1. For n >= 3, a(n) = 1 + A114600(n-2)*A114600(n-1).

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =7a(5) =22a(6) =78a(7) =144a(8) =40a(9) =16a(10) =11a(11) =23a(12) =254a(13) =2922a(14) =61850a(15) =602420a(16) =409448a(17) =42038a(18) =2669414a(19) =38065410a(20) =255320214a(21) =315752716934