A098948 Numbers where 7 is the only odd decimal digit.

7, 27, 47, 67, 70, 72, 74, 76, 77, 78, 87, 207, 227, 247, 267, 270, 272, 274, 276, 277, 278, 287, 407, 427, 447, 467, 470, 472, 474, 476, 477, 478, 487, 607, 627, 647, 667, 670, 672, 674, 676, 677, 678, 687, 700, 702, 704, 706, 707, 708, 720, 722, 724, 726

Offset: 1

Author

Eric Angelini, Oct 21 2004

Keywords

• base
• easy
• nonn

Comments

This is a 10-automatic language. - Charles R Greathouse IV, Oct 03 2011

Links

• Index entries for 10-automatic sequences

Programs

Maple

q:= n-> is(select(c-> c::odd, {convert(n, base, 10)[]})={7}):
select(q, [$1..887])[];  # Alois P. Heinz, Jul 27 2021

Mathematica

Select[Range[1000],Union[Select[IntegerDigits[#],OddQ]]=={7}&] (* Harvey P. Dale, May 24 2012 *)

Perl

for (0..1000) {
    print "$_, " if (/^[024678]*7[024678]*$/)
} # Charles R Greathouse IV, Oct 05 2011

Python

def ok(n): return set("13579") & set(str(n)) == {'7'}
print(list(filter(ok, range(727)))) # Michael S. Branicky, Jul 27 2021