Plaindromes: numbers whose digits in base 7 are in nondecreasing order.

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =4a(5) =5a(6) =6a(7) =8a(8) =9a(9) =10a(10) =11a(11) =12a(12) =13a(13) =16a(14) =17a(15) =18a(16) =19a(17) =20a(18) =24a(19) =25a(20) =26a(21) =27a(22) =32a(23) =33a(24) =34a(25) =40a(26) =41a(27) =48a(28) =57a(29) =58