Numbers n such that string 3,7 occurs in the base 10 representation of n but not of n-1.

Terms

a(0) =37a(1) =137a(2) =237a(3) =337a(4) =370a(5) =437a(6) =537a(7) =637a(8) =737a(9) =837a(10) =937a(11) =1037a(12) =1137a(13) =1237a(14) =1337a(15) =1370a(16) =1437a(17) =1537a(18) =1637a(19) =1737a(20) =1837a(21) =1937a(22) =2037a(23) =2137a(24) =2237a(25) =2337a(26) =2370a(27) =2437a(28) =2537a(29) =2637