A081434 Numbers such that RevBinary() = RevDecimal(), where RevDecimal(n) is the decimal reversal of n (A004086) and RevBinary(n) is the binary reversal of n (A030101).

0, 1, 3, 5, 7, 9, 33, 92, 99, 313, 585, 717, 732, 759, 957, 5485, 5845, 7447, 9009, 15351, 32223, 39993, 53235, 53835, 71869, 73737, 77360, 96817, 319773, 377913, 585585, 1758571, 1934391, 1979791, 3129213, 5071705, 5259525, 5841485, 13162800

Offset: 1

Author

Reinhard Zumkeller, Mar 20 2003

Keywords

• nonn
• base

Links

• Amiram Eldar, Table of n, a(n) for n = 1..55

Crossrefs

Cf. A004086, A030101.

Cf. A007632, A081433, A007088.

Programs

Mathematica

Select[Range[0, 100000], SameQ @@ IntegerReverse[#, {2, 10}] &] (* Amiram Eldar, Aug 05 2025 *)

PARI

isok(k) = fromdigits(Vecrev(binary(k)), 2) == fromdigits(Vecrev(digits(k))); \\ Amiram Eldar, Aug 05 2025

Python

def ok(n): return int(bin(n)[:1:-1], 2) == int(str(n)[::-1])
print([k for k in range(10**7) if ok(k)]) # Michael S. Branicky, Jan 30 2023

Formula

A030101(a(n)) = A004086(a(n)).

Extensions

More terms from Harry J. Smith, Dec 19 2007