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A043432 Numbers k such that number of 2's in base 8 is 4. 1
1170, 5266, 8338, 8850, 9234, 9298, 9346, 9354, 9360, 9361, 9363, 9364, 9365, 9366, 9367, 9370, 9378, 9386, 9394, 9402, 9426, 9490, 9554, 9618, 9682, 9874, 10386, 10898, 11410, 11922, 13458, 17554, 21650, 25746, 29842 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MAPLE

F:= proc(d) local r, L, M, S, Res; # to get all terms < 8^d

   Res:= NULL;

   for S in combinat:-choose(d, d-4) do

     L:= Vector(d, 2);

     for r from 0 to 7^(d-4)-1 do

       M:= subs(2=7, convert(r+7^(d-4), base, 7)[1..d-4]);

       L[S]:= Vector(M);

       Res:= Res, add(8^(i-1)*L[i], i=1..d);

     od

   od;

   sort([Res]);

end proc:

F(6); # Robert Israel, Mar 20 2018

MATHEMATICA

Select[Range[0, 30000], DigitCount[#, 8, 2]==4 &] (* Vincenzo Librandi, Mar 21 2018 *)

PROG

(PARI) isok(n) = #select(x->(x==2), digits(n, 8)) == 4; \\ Michel Marcus, Mar 21 2018

CROSSREFS

Sequence in context: A185468 A209825 A264688 * A065703 A202487 A230946

Adjacent sequences:  A043429 A043430 A043431 * A043433 A043434 A043435

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified September 25 21:48 EDT 2020. Contains 337344 sequences. (Running on oeis4.)