A043045 a(n)=(s(n)+2)/3, where s(n)=n-th base 3 palindrome that starts with 1.

1, 2, 4, 5, 6, 10, 14, 18, 28, 31, 34, 38, 41, 44, 48, 51, 54, 82, 94, 106, 110, 122, 134, 138, 150, 162, 244, 253, 262, 274, 283, 292, 304, 313, 322, 326, 335, 344, 356, 365, 374, 386, 395, 404, 408, 417, 426, 438, 447, 456, 468

Offset

1,2

Links

Table of n, a(n) for n=1..51.

Mathematica

b3pQ[n_]:=Module[{idn3=IntegerDigits[n, 3]}, idn3[[1]]==1&&Reverse[idn3] == idn3]; (#+2)/3&/@Select[Range[2000], b3pQ] (* Harvey P. Dale, Dec 08 2018 *)

Crossrefs

Sequence in context: A171165 A039036 A219046 * A091678 A080053 A101964

Adjacent sequences: A043042 A043043 A043044 * A043046 A043047 A043048

Keyword

nonn,base

Author

Clark Kimberling

Status

approved