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

Terms

a(0) =1a(1) =7a(2) =43a(3) =44a(4) =45a(5) =46a(6) =47a(7) =48a(8) =49a(9) =295a(10) =303a(11) =311a(12) =319a(13) =327a(14) =335a(15) =343a(16) =2059a(17) =2066a(18) =2073a(19) =2080a(20) =2087a(21) =2094a(22) =2101a(23) =2109a(24) =2116a(25) =2123a(26) =2130a(27) =2137a(28) =2144a(29) =2151