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A033032 Numbers all of whose base 6 digits are odd. 1
1, 3, 5, 7, 9, 11, 19, 21, 23, 31, 33, 35, 43, 45, 47, 55, 57, 59, 67, 69, 71, 115, 117, 119, 127, 129, 131, 139, 141, 143, 187, 189, 191, 199, 201, 203, 211, 213, 215, 259, 261, 263, 271, 273, 275, 283, 285, 287, 331, 333, 335, 343 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

FORMULA

If (3^d-1)/2 <= n < (3^(d+1)-1)/2, then a(n+3^d) = a(n) + 6^n, a(n+2*3^d) = a(n) + 2*6^n, and a(n+3^(d+1)) = a(n) + 5*6^n. - Robert Israel, Aug 16 2018

MAPLE

g:= proc(t, d) local L;

    L:= convert(3^d+t, base, 3);

    add((2*L[i]+1)*6^(i-1), i=1..d);

end proc:

seq(seq(g(t, d), t=0..3^d-1), d=1..4); # Robert Israel, Aug 16 2018

PROG

(PARI) isok(n) = (n) && (#select(x->((x%2)==0), digits(n, 6)) == 0); \\ Michel Marcus, Aug 17 2018

CROSSREFS

Sequence in context: A152484 A071643 A039578 * A103148 A211138 A178995

Adjacent sequences:  A033029 A033030 A033031 * A033033 A033034 A033035

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified May 11 05:25 EDT 2021. Contains 343784 sequences. (Running on oeis4.)