Place where n-th 1 occurs in A023120.

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =7a(5) =9a(6) =12a(7) =15a(8) =19a(9) =23a(10) =27a(11) =32a(12) =37a(13) =42a(14) =48a(15) =54a(16) =61a(17) =68a(18) =75a(19) =83a(20) =91a(21) =99a(22) =108a(23) =117a(24) =127a(25) =137a(26) =147a(27) =158a(28) =169a(29) =180