Numbers n such that string 3,0 occurs in the base 10 representation of n but not of n+1.

Terms

a(0) =30a(1) =130a(2) =230a(3) =309a(4) =330a(5) =430a(6) =530a(7) =630a(8) =730a(9) =830a(10) =930a(11) =1030a(12) =1130a(13) =1230a(14) =1309a(15) =1330a(16) =1430a(17) =1530a(18) =1630a(19) =1730a(20) =1830a(21) =1930a(22) =2030a(23) =2130a(24) =2230a(25) =2309a(26) =2330a(27) =2430a(28) =2530a(29) =2630