A294601 Numbers with exactly one odd decimal digit.

1, 3, 5, 7, 9, 10, 12, 14, 16, 18, 21, 23, 25, 27, 29, 30, 32, 34, 36, 38, 41, 43, 45, 47, 49, 50, 52, 54, 56, 58, 61, 63, 65, 67, 69, 70, 72, 74, 76, 78, 81, 83, 85, 87, 89, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 120, 122, 124, 126, 128, 140, 142, 144, 146, 148, 160, 162, 164, 166, 168, 180

Offset: 1

Author

Robert Israel, Nov 03 2017

Keywords

• nonn
• base
• look

Comments

First differs from A054684 at position 56.

Numbers n such that A196564(n) = 1. - Felix Fröhlich, Nov 03 2017

There are (1+4*d)*5^(d-1) = 5*A081040(d+1) terms with d digits. - Robert Israel, Nov 06 2017

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A014263, A054684, A081040, A196564, A275775.

Programs

Maple

Res:= NULL:
for t from 0 to 1000 do
  if nops(select(type,convert(t,base,10),odd))=1 then Res:= Res,t fi
od:
Res;

Mathematica

Select[Range@ 200, Count[IntegerDigits@ #, ?OddQ] == 1 &] (* _Michael De Vlieger, Nov 03 2017 *)

PARI

a196564(n) = #select(x->x%2, digits(n)) \\ after Michel Marcus
is(n) = a196564(n)==1 \\ Felix Fröhlich, Nov 03 2017