A031011 Position of n-th 3 in A031007.

3, 13, 27, 36, 38, 40, 41, 42, 44, 46, 48, 55, 69, 83, 100, 121, 142, 155, 158, 161, 163, 164, 167, 170, 173, 184, 205, 226, 247, 268, 289, 302, 305, 308, 310, 311, 314, 317, 320, 331, 352, 373, 387, 390, 393, 394, 396, 399, 402

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Programs

Mathematica

(Position[Flatten[Table[Reverse[IntegerDigits[n,7]],{n,0,200}]],3]//Flatten)-1 (* Harvey P. Dale, Sep 10 2024 *)