Numbers k such that k concatenated with k+3 is a lucky number.

Terms

a(0) =2a(1) =6a(2) =14a(3) =20a(4) =24a(5) =32a(6) =48a(7) =50a(8) =66a(9) =68a(10) =78a(11) =84a(12) =108a(13) =120a(14) =128a(15) =134a(16) =146a(17) =156a(18) =162a(19) =200a(20) =210a(21) =218a(22) =224a(23) =228a(24) =254a(25) =266a(26) =270a(27) =284a(28) =290a(29) =306