A043059 a(n)=(s(n)+6)/7, where s(n)=n-th base 7 palindrome that starts with 1.

1, 2, 8, 9, 10, 11, 12, 13, 14, 50, 58, 66, 74, 82, 90, 98, 344, 351, 358, 365, 372, 379, 386, 394, 401, 408, 415, 422, 429, 436, 444, 451, 458, 465, 472, 479, 486, 494, 501, 508, 515, 522, 529, 536, 544, 551, 558, 565, 572, 579