Position of n-th 5 in A031007.

Terms

a(0) =5a(1) =17a(2) =31a(3) =45a(4) =59a(5) =64a(6) =66a(7) =68a(8) =70a(9) =72a(10) =73a(11) =74a(12) =76a(13) =87a(14) =106a(15) =127a(16) =148a(17) =169a(18) =190a(19) =197a(20) =200a(21) =203a(22) =206a(23) =209a(24) =211a(25) =212a(26) =215a(27) =232a(28) =253a(29) =274