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A045058 Numbers whose base-4 representation contains exactly four 0's and one 2. 1
512, 1026, 1032, 1056, 1152, 1536, 2049, 2051, 2052, 2060, 2064, 2096, 2112, 2240, 2304, 2816, 3074, 3080, 3104, 3200, 3584, 4102, 4105, 4107, 4110, 4114, 4120, 4129, 4131, 4132, 4140, 4146, 4152, 4162, 4168, 4192, 4225 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MAPLE
dmax:= 8: # to get all terms < 4^dmax
T[1, 1, 0]:= {}: T[1, 0, 1]:= {2}: T[1, 0, 0]:= {1, 3}:
for d from 2 to dmax do
for a from 0 to max(d-1, 4) do
for b from 0 to max(d-a, 1) do
T[d, a, b]:= {}:
if a + b <= d-1 and a < d-1 then
T[d, a, b]:= T[d, a, b] union map(t -> (4*t+1, 4*t+3), T[d-1, a, b])
fi;
if a >= 1 then
T[d, a, b]:= T[d, a, b] union map(t -> 4*t, T[d-1, a-1, b])
fi;
if b >= 1 and a < d-1 then
T[d, a, b]:= T[d, a, b] union map(t -> 4*t+2, T[d-1, a, b-1])
fi;
od od od:
sort([seq](op(T[d, 4, 1]), d=5..dmax)); # Robert Israel, Jun 29 2017
MATHEMATICA
Select[Range[4500], DigitCount[#, 4, 0]==4&&DigitCount[#, 4, 2]==1&] (* Harvey P. Dale, May 26 2018 *)
CROSSREFS
Cf. A007090.
Sequence in context: A066648 A043423 A341886 * A220017 A234879 A202454
KEYWORD
nonn,base
AUTHOR
STATUS
approved

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Last modified February 29 03:50 EST 2024. Contains 370401 sequences. (Running on oeis4.)