Numbers k such that 3 and 7 occur juxtaposed in the base-9 representation of k but not of k-1.

Terms

a(0) =34a(1) =66a(2) =115a(3) =147a(4) =196a(5) =228a(6) =277a(7) =306a(8) =358a(9) =390a(10) =439a(11) =471a(12) =520a(13) =552a(14) =594a(15) =633a(16) =682a(17) =714a(18) =763a(19) =795a(20) =844a(21) =876a(22) =925a(23) =957a(24) =1006a(25) =1035a(26) =1087a(27) =1119a(28) =1168a(29) =1200