A043509 Numbers having exactly one 5 in base 10.

5, 15, 25, 35, 45, 50, 51, 52, 53, 54, 56, 57, 58, 59, 65, 75, 85, 95, 105, 115, 125, 135, 145, 150, 151, 152, 153, 154, 156, 157, 158, 159, 165, 175, 185, 195, 205, 215, 225, 235, 245, 250, 251, 252, 253, 254, 256, 257, 258, 259

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base
• easy

Links

• Enrique Pérez Herrero, Table of n, a(n) for n = 1..2000
• Index entries for 10-automatic sequences.

Crossrefs

Cf. A043489, A043493, A043497, A043501, A043505, A043513, A043517, A043521, A043525, A011535.

Programs

Mathematica

Select[Range[9000],DigitCount[#,10,5]==1&] (* Enrique Pérez Herrero, Nov 29 2013 *)

Formula

a(n) ≍ n^k log n, with k = log 9/log 10 = 0.9542425... = A104139. - Charles R Greathouse IV, Nov 01 2022