Numbers k such that string 5,4 occurs in the base 7 representation of k but not of k-1.

Terms

a(0) =39a(1) =88a(2) =137a(3) =186a(4) =235a(5) =273a(6) =284a(7) =333a(8) =382a(9) =431a(10) =480a(11) =529a(12) =578a(13) =616a(14) =627a(15) =676a(16) =725a(17) =774a(18) =823a(19) =872a(20) =921a(21) =959a(22) =970a(23) =1019a(24) =1068a(25) =1117a(26) =1166a(27) =1215a(28) =1264a(29) =1302