A043061 (s(n)+4)/7, where s(n)=n-th base 7 palindrome that starts with 3.

1, 4, 22, 23, 24, 25, 26, 27, 28, 148, 156, 164, 172, 180, 188, 196, 1030, 1037, 1044, 1051, 1058, 1065, 1072, 1080, 1087, 1094, 1101, 1108, 1115, 1122, 1130, 1137, 1144, 1151, 1158, 1165, 1172, 1180, 1187, 1194, 1201, 1208

Offset

1,2

Links

Table of n, a(n) for n=1..42.

Mathematica

b7p3Q[n_]:=Module[{idn7=IntegerDigits[n, 7]}, idn7[[1]]==3&&idn7 == Reverse[ idn7]]; (#+4)/7&/@Select[Range[10000], b7p3Q] (* Harvey P. Dale, Apr 27 2020 *)

Crossrefs

Sequence in context: A121006 A268924 A185866 * A009925 A059653 A022385

Adjacent sequences: A043058 A043059 A043060 * A043062 A043063 A043064

Keyword

nonn,base

Author

Clark Kimberling

Status

approved