Numbers k such that k concatenated with k+7 is a lucky number.

Terms

a(0) =6a(1) =12a(2) =28a(3) =30a(4) =46a(5) =52a(6) =64a(7) =70a(8) =72a(9) =78a(10) =82a(11) =88a(12) =126a(13) =148a(14) =160a(15) =166a(16) =184a(17) =198a(18) =210a(19) =226a(20) =228a(21) =268a(22) =286a(23) =298a(24) =300a(25) =306a(26) =334a(27) =346a(28) =364a(29) =376