Numbers k such that string 3,6 occurs in the base 7 representation of k but not of k-1.

Terms

a(0) =27a(1) =76a(2) =125a(3) =174a(4) =189a(5) =223a(6) =272a(7) =321a(8) =370a(9) =419a(10) =468a(11) =517a(12) =532a(13) =566a(14) =615a(15) =664a(16) =713a(17) =762a(18) =811a(19) =860a(20) =875a(21) =909a(22) =958a(23) =1007a(24) =1056a(25) =1105a(26) =1154a(27) =1203a(28) =1218a(29) =1252