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A045134 Numbers whose base-4 representation contains no 2's and exactly one 3. 1
3, 7, 12, 13, 19, 23, 28, 29, 48, 49, 52, 53, 67, 71, 76, 77, 83, 87, 92, 93, 112, 113, 116, 117, 192, 193, 196, 197, 208, 209, 212, 213, 259, 263, 268, 269, 275, 279, 284, 285, 304, 305, 308, 309, 323, 327, 332, 333, 339, 343, 348 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
From Robert Israel, Sep 20 2016: (Start)
a(m+(n+1)*2^n) = a(m) + 4^(n+1) for 1 <= m <= (n+1)*2^n.
a(m+(n+1)*2^n) = A000695(m-(n+1)*2^n-1) + 3*4^(n+1) for (n+1)*2^n < m <= (n+2)*2^n. (End)
MAPLE
N:= 5: # to get all terms < 4^(N+1)
B0:= {0, 1}:
B1:= {3}:
for d from 1 to N do
B1:= B1 union map(`+`, B0, 3*4^d) union map(`+`, B1, 4^d);
B0:= B0 union map(`+`, B0, 4^d);
od:
sort(convert(B1, list)); # Robert Israel, Sep 20 2016
MATHEMATICA
Select[Range[400], DigitCount[#, 4, 2]==0&&DigitCount[#, 4, 3]==1&] (* Harvey P. Dale, Dec 25 2012 *)
CROSSREFS
Sequence in context: A056772 A024614 A230109 * A215631 A081695 A290955
KEYWORD
nonn,base
AUTHOR
STATUS
approved

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Last modified April 21 04:17 EDT 2024. Contains 371850 sequences. (Running on oeis4.)