Smallest k such that A349949(k) = n, or -1 if no such k exists.

Terms

a(0) =2a(1) =3a(2) =8a(3) =15a(4) =63a(5) =120a(6) =440a(7) =945a(8) =2079a(9) =4095a(10) =21735a(11) =98175a(12) =133056a(13) =395199a(14) =338625a(15) =1890945a(16) =3501576a(17) =8390304a(18) =35820225a(19) =126775935a(20) =149848335a(21) =879207616a(22) =302464800