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A379835
Number of 1's in binary expansion of Lucas(n).
1
1, 1, 2, 1, 3, 3, 2, 4, 5, 3, 6, 5, 3, 3, 6, 5, 7, 9, 6, 5, 9, 10, 9, 11, 6, 9, 7, 10, 15, 11, 10, 15, 13, 11, 11, 15, 15, 12, 15, 17, 15, 11, 14, 15, 20, 15, 18, 17, 13, 11, 22, 20, 23, 23, 19, 22, 22, 22, 28, 25, 23, 19, 25, 27, 27, 24, 26, 25, 23, 27, 23, 27
OFFSET
0,3
LINKS
FORMULA
a(n) = A000120(A000032(n)).
EXAMPLE
a(10) = 6 because Lucas(10) = 123 is 1111011_2, which has 6 one bits.
MAPLE
f:= n -> convert(convert(combinat:-fibonacci(n+1) + combinat:-fibonacci(n-1), base, 2), `+`):
map(f, [$0..100]); # Robert Israel, May 15 2026
MATHEMATICA
Table[DigitCount[LucasL[n], 2][[1]], {n, 0, 200}]
PROG
(Magma) [&+Intseq(Lucas(n), 2): n in [0..100]];
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Vincenzo Librandi, Jan 05 2025
STATUS
approved