Plaindromes: numbers whose digits in base 6 are in nondecreasing order.

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =4a(5) =5a(6) =7a(7) =8a(8) =9a(9) =10a(10) =11a(11) =14a(12) =15a(13) =16a(14) =17a(15) =21a(16) =22a(17) =23a(18) =28a(19) =29a(20) =35a(21) =43a(22) =44a(23) =45a(24) =46a(25) =47a(26) =50a(27) =51a(28) =52a(29) =53