A081431 - OEIS

%I #17 Jan 30 2023 12:29:05

%S 0,1,1,3,1,5,3,7,1,9,1,13,21,31,37,51,47,113,69,109,1,3,13,1,21,11,31,

%T 9,37,29,3,11,29,33,53,43,63,73,101,93,1,7,3,17,13,27,1,41,21,61,5,15,

%U 19,49,45,59,65,105,85,125,3,1,11,9,29,7,33,25,53,3,7,17,27,41

%N RevBinary(RevDecimal(n)), where RevBinary(m) is the binary reversal of m (A030101) and RevDecimal(m) is the decimal reversal of m (A004086).

%H Harvey P. Dale, <a href="/A081431/b081431.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) = A030101(A004086(n)). - _Michel Marcus_, Jan 30 2023

%t Table[IntegerReverse[IntegerReverse[n],2],{n,0,80}] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Dec 03 2018 *)

%o (Python)

%o def a(n): return int(bin(int(str(n)[::-1]))[:1:-1], 2)

%o print([a(n) for n in range(74)]) # _Michael S. Branicky_, Jan 30 2023

%o (PARI) a(n) = fromdigits(Vecrev(binary(fromdigits(Vecrev(digits(n))))), 2); \\ _Michel Marcus_, Jan 30 2023

%Y Cf. A004086, A030101.

%Y Cf. A081432, A081433, A007088.

%K nonn,base

%O 0,4

%A _Reinhard Zumkeller_, Mar 20 2003