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A344346
Numbers k which have an odd number of trailing zeros in their binary reflected Gray code A014550(k).
1
3, 4, 11, 12, 15, 16, 19, 20, 27, 28, 35, 36, 43, 44, 47, 48, 51, 52, 59, 60, 63, 64, 67, 68, 75, 76, 79, 80, 83, 84, 91, 92, 99, 100, 107, 108, 111, 112, 115, 116, 123, 124, 131, 132, 139, 140, 143, 144, 147, 148, 155, 156, 163, 164, 171, 172, 175, 176, 179, 180
OFFSET
1,1
COMMENTS
Numbers k such that A050605(k-1) is odd.
Numbers k such that A136480(k) is even.
The asymptotic density of this sequence is 1/3.
LINKS
Eric Weisstein's World of Mathematics, Gray Code.
Wikipedia, Gray code.
FORMULA
a(n) = A081706(n) + 1. - Hugo Pfoertner, May 16 2021
EXAMPLE
3 is a term since its Gray code, 10, has 1 trailing zero, and 1 is odd.
15 is a term since its Gray code, 1000, has 3 trailing zeros, and 3 is odd.
MATHEMATICA
Select[Range[180], OddQ @ IntegerExponent[# * (# + 1)/2, 2] &]
CROSSREFS
Similar sequences: A001950 (Zeckendorf), A036554 (binary), A145204 (ternary), A217319 (quaternary), A232745 (factorial), A342050 (primorial).
Sequence in context: A339578 A244005 A228236 * A047457 A226632 A098377
KEYWORD
nonn,base,easy
AUTHOR
Amiram Eldar, May 15 2021
STATUS
approved