Numbers n such that string 4,2 occurs in the base 10 representation of n but not of n-1.

Terms

a(0) =42a(1) =142a(2) =242a(3) =342a(4) =420a(5) =442a(6) =542a(7) =642a(8) =742a(9) =842a(10) =942a(11) =1042a(12) =1142a(13) =1242a(14) =1342a(15) =1420a(16) =1442a(17) =1542a(18) =1642a(19) =1742a(20) =1842a(21) =1942a(22) =2042a(23) =2142a(24) =2242a(25) =2342a(26) =2420a(27) =2442a(28) =2542a(29) =2642