Numbers k such that k surrounded by digit '9' is a lucky number.

Terms

a(0) =7a(1) =13a(2) =24a(3) =33a(4) =34a(5) =39a(6) =40a(7) =42a(8) =54a(9) =64a(10) =78a(11) =97a(12) =99a(13) =103a(14) =105a(15) =108a(16) =112a(17) =123a(18) =126a(19) =127a(20) =129a(21) =132a(22) =133a(23) =139a(24) =142a(25) =147a(26) =150a(27) =163a(28) =172a(29) =177