Positions of odd numbers in A024975.

Terms

a(0) =2a(1) =4a(2) =6a(3) =9a(4) =11a(5) =13a(6) =14a(7) =16a(8) =18a(9) =21a(10) =23a(11) =25a(12) =27a(13) =29a(14) =30a(15) =33a(16) =35a(17) =36a(18) =39a(19) =40a(20) =42a(21) =45a(22) =46a(23) =49a(24) =50a(25) =54a(26) =56a(27) =57a(28) =60a(29) =61