A333415 Odd positive integers in base 2 read backwards.

1, 11, 101, 111, 1001, 1101, 1011, 1111, 10001, 11001, 10101, 11101, 10011, 11011, 10111, 11111, 100001, 110001, 101001, 111001, 100101, 110101, 101101, 111101, 100011, 110011, 101011, 111011, 100111, 110111, 101111, 111111, 1000001, 1100001, 1010001, 1110001, 1001001

Offset: 1

Author

Devansh Singh, Mar 20 2020

Keywords

• nonn
• base

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A007088, A145341.

Cf. A004086, A099821.

Programs

Maple

f:= proc(n) local L,i;
 L:= convert(n,base,2);
 add(L[-i]*10^(i-1),i=1..nops(L));
end proc
map(f, [seq(i,i=1..100,2)]); # Robert Israel, May 19 2024

Mathematica

Table[FromDigits[Reverse[IntegerDigits[n, 2]]], {n, 1, 75, 2}] (* Amiram Eldar, Apr 27 2020 *)

PARI

a(n) = fromdigits(Vecrev(binary(2*n-1))); \\ Michel Marcus, May 19 2024

Formula

From Michel Marcus, Apr 23 2020: (Start)

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

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

Extensions

New name, a(1)=1 and more terms from Michel Marcus, Apr 23 2020