a(n) = index of the first occurrence of n in A088606.

Terms

a(0) =2a(1) =5a(2) =7a(3) =8a(4) =26a(5) =40a(6) =134a(7) =160a(8) =107a(9) =172a(10) =35a(11) =79a(12) =739a(13) =267a(14) =137a(15) =1119a(16) =97a(17) =1498a(18) =983a(19) =1404a(20) =2193a(21) =1206a(22) =3262a(23) =369a(24) =3256a(25) =2728a(26) =1406a(27) =3483a(28) =6771a(29) =2226