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A045047 Numbers whose base-4 representation contains exactly two 0's and no 2's. 1
16, 48, 65, 67, 68, 76, 80, 112, 193, 195, 196, 204, 208, 240, 261, 263, 269, 271, 273, 275, 276, 284, 305, 307, 308, 316, 321, 323, 324, 332, 336, 368, 449, 451, 452, 460, 464, 496, 773, 775, 781, 783, 785, 787, 788, 796, 817 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
If k is in the sequence, then so are 4*k+1 and 4*k+3 but not 4*k or 4*k+2. - Robert Israel, Jan 19 2023
LINKS
MAPLE
filter:= proc(n) local L; L:= convert(n, base, 4);
not member(2, L) and numboccur(0, L)=2
end proc:
select(filter, [$1..1000]); # Robert Israel, Jan 19 2023
CROSSREFS
Cf. A007090.
Sequence in context: A322448 A354181 A264164 * A239344 A195087 A348882
KEYWORD
nonn,base
AUTHOR
STATUS
approved

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Last modified May 20 11:05 EDT 2024. Contains 372712 sequences. (Running on oeis4.)