A043074 a(n)=(s(n)+6)/9, where s(n)=n-th base 9 palindrome that starts with 3.

1, 4, 28, 29, 30, 31, 32, 33, 34, 35, 36, 244, 254, 264, 274, 284, 294, 304, 314, 324, 2188, 2197, 2206, 2215, 2224, 2233, 2242, 2251, 2260, 2270, 2279, 2288, 2297, 2306, 2315, 2324, 2333, 2342, 2352, 2361, 2370, 2379, 2388, 2397

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base

Programs

Mathematica

b9pQ[n_]:=Module[{idn9=IntegerDigits[9n-6,9]},idn9==Reverse[idn9]&&idn9[[1]]==3]; Select[ Range[2500],b9pQ] (* Harvey P. Dale, May 19 2023 *)