Numbers whose base-7 representation contains exactly three 6's.

Terms

a(0) =342a(1) =685a(2) =1028a(3) =1371a(4) =1714a(5) =2057a(6) =2106a(7) =2155a(8) =2204a(9) =2253a(10) =2302a(11) =2351a(12) =2358a(13) =2365a(14) =2372a(15) =2379a(16) =2386a(17) =2393a(18) =2394a(19) =2395a(20) =2396a(21) =2397a(22) =2398a(23) =2399a(24) =2743a(25) =3086a(26) =3429a(27) =3772a(28) =4115a(29) =4458