login
A033033
Numbers all of whose base 7 digits are odd.
4
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
1,2
LINKS
EXAMPLE
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
MATHEMATICA
Select[Range[600], AllTrue[IntegerDigits[#, 7], OddQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Sep 28 2014 *)
PROG
(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
(Magma) [m:m in [1..600]| Intseq(m, 7) subset {1, 3, 5}]; // Marius A. Burtea, Aug 24 2019
CROSSREFS
Sequence in context: A287236 A305378 A362935 * A211704 A275813 A356037
KEYWORD
nonn,easy,base
STATUS
approved