A033033 Numbers all of whose base 7 digits are odd.
1, 3, 5, 8, 10, 12, 22, 24, 26, 36, 38, 40, 57, 59, 61, 71, 73, 75, 85, 87, 89, 155, 157, 159, 169, 171, 173, 183, 185, 187, 253, 255, 257, 267, 269, 271, 281, 283, 285, 400, 402, 404, 414, 416, 418, 428, 430, 432, 498, 500, 502, 512
Offset: 1
Examples
38 in base 7 is 53_7. All the digits of 38 in base 7; 5 and 3; are odd. So 38 is in the sequence. - _David A. Corneth_, Aug 24 2019
Links
- David A. Corneth, Table of n, a(n) for n = 1..10000
Programs
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Magma
[m:m in [1..600]| Intseq(m,7) subset {1,3,5}]; // Marius A. Burtea, Aug 24 2019 -
Mathematica
Select[Range[600],AllTrue[IntegerDigits[#,7],OddQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Sep 28 2014 *)
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PARI
is(n) = {my(d = Set(digits(n, 7))); for(i = 1, #d, if(d[i]%2 == 0, return(0))); 1} \\ David A. Corneth, Aug 24 2019