a(n) is the least k such that A261865(k) = A005117(n).

Terms

a(0) =1a(1) =3a(2) =40a(3) =61a(4) =23a(5) =170a(6) =99a(7) =54a(8) =662a(9) =30a(10) =993a(11) =880a(12) =307a(13) =877a(14) =1007a(15) =3523a(16) =8562a(17) =5039a(18) =18757a(19) =12724a(20) =9819a(21) =5602a(22) =2512a(23) =184a(24) =10597a(25) =33155a(26) =43913a(27) =8091a(28) =16060a(29) =59212