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

Terms

a(0) =44a(1) =144a(2) =244a(3) =344a(4) =440a(5) =544a(6) =644a(7) =744a(8) =844a(9) =944a(10) =1044a(11) =1144a(12) =1244a(13) =1344a(14) =1440a(15) =1544a(16) =1644a(17) =1744a(18) =1844a(19) =1944a(20) =2044a(21) =2144a(22) =2244a(23) =2344a(24) =2440a(25) =2544a(26) =2644a(27) =2744a(28) =2844a(29) =2944