Position of n-th 9 in A031312.

Terms

a(0) =5a(1) =15a(2) =25a(3) =35a(4) =45a(5) =55a(6) =65a(7) =75a(8) =85a(9) =86a(10) =88a(11) =90a(12) =92a(13) =94a(14) =95a(15) =110a(16) =125a(17) =140a(18) =155a(19) =170a(20) =185a(21) =200a(22) =215a(23) =230a(24) =232a(25) =235a(26) =238a(27) =241a(28) =244a(29) =245