A031003 Position of n-th 4 in A030998.

4, 16, 30, 44, 49, 51, 53, 55, 57, 58, 59, 61, 72, 86, 105, 126, 147, 168, 176, 179, 182, 185, 188, 189, 191, 194, 210, 231, 252, 273, 294, 315, 323, 326, 329, 332, 335, 336, 338, 341, 357, 378, 399, 420, 441, 462, 470, 473, 476

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Programs

Mathematica

Flatten[Position[Flatten[IntegerDigits[#,7]&/@Range[0,200]],4]]-1 (* Harvey P. Dale, May 06 2014 *)