A341273 - OEIS

%I #13 Feb 09 2021 11:54:42

%S 0,0,0,7,0,7,7,7,0,25,42,75,76,45,30,7,0,25,82,51,52,85,30,7,25,25,30,

%T 25,30,25,30,30,0,97,42,51,52,45,102,7,42,45,42,42,45,45,42,45,52,51,

%U 51,51,52,52,52,51,120,25,42,51,52,45,30,127,0,97,82,75

%N If A261283(n) = 0, then a(n) = n, otherwise a(n) is obtained by flipping the A261283(n)-th rightmost bit in the binary expansion of n.

%C All terms belong to A075926.

%H Rémy Sigrist, <a href="/A341273/b341273.txt">Table of n, a(n) for n = 0..32768</a>

%F A261283(a(n)) = 0.

%F a(a(n)) = a(n).

%F a(n) = n iff n belongs to A075926.

%F a(2^k) = 0 for any k >= 0.

%e For n = 7:

%e - A261283(7) = 0,

%e - so a(7) = 7.

%e For n = 43:

%e - A261283(43) = 1,

%e - so a(43) is obtained by flipping the rightmost binary digit in 43,

%e - a(43) = 42.

%o (PARI) a(n) = { my (m=n, x=0); while (m, my (v=valuation(m, 2)); x=bitxor(x, v+1); m-=2^v); if (x, bitxor(n, 2^(x-1)), n) }

%Y Cf. A075926, A261283.

%K nonn,look,base

%O 0,4

%A _Rémy Sigrist_, Feb 08 2021