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A333415 Odd positive integers in base 2 read backwards. 1

%I #45 May 20 2024 10:30:45

%S 1,11,101,111,1001,1101,1011,1111,10001,11001,10101,11101,10011,11011,

%T 10111,11111,100001,110001,101001,111001,100101,110101,101101,111101,

%U 100011,110011,101011,111011,100111,110111,101111,111111,1000001,1100001,1010001,1110001,1001001

%N Odd positive integers in base 2 read backwards.

%H Robert Israel, <a href="/A333415/b333415.txt">Table of n, a(n) for n = 1..10000</a>

%F From _Michel Marcus_, Apr 23 2020: (Start)

%F a(n) = A007088(A145341(n)).

%F a(n) = A004086(A099821(n)). (End)

%p f:= proc(n) local L,i;

%p L:= convert(n,base,2);

%p add(L[-i]*10^(i-1),i=1..nops(L));

%p end proc

%p map(f, [seq(i,i=1..100,2)]); # _Robert Israel_, May 19 2024

%t Table[FromDigits[Reverse[IntegerDigits[n, 2]]], {n, 1, 75, 2}] (* _Amiram Eldar_, Apr 27 2020 *)

%o (PARI) a(n) = fromdigits(Vecrev(binary(2*n-1))); \\ _Michel Marcus_, May 19 2024

%Y Cf. A007088, A145341.

%Y Cf. A004086, A099821.

%K nonn,base

%O 1,2

%A _Devansh Singh_, Mar 20 2020

%E New name, a(1)=1 and more terms from _Michel Marcus_, Apr 23 2020

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Last modified September 2 15:48 EDT 2024. Contains 375613 sequences. (Running on oeis4.)