Position of n-th 1 in A031027.

Terms

a(0) =1a(1) =5a(2) =6a(3) =7a(4) =13a(5) =16a(6) =25a(7) =29a(8) =32a(9) =35a(10) =40a(11) =41a(12) =45a(13) =46a(14) =48a(15) =61a(16) =66a(17) =67a(18) =76a(19) =81a(20) =85a(21) =87a(22) =92a(23) =109a(24) =110a(25) =113a(26) =121a(27) =128a(28) =133a(29) =138