A142151 a(n) = OR{k XOR (n-k): 0<=k<=n}.

0, 1, 2, 3, 6, 5, 6, 7, 14, 13, 14, 11, 14, 13, 14, 15, 30, 29, 30, 27, 30, 29, 30, 23, 30, 29, 30, 27, 30, 29, 30, 31, 62, 61, 62, 59, 62, 61, 62, 55, 62, 61, 62, 59, 62, 61, 62, 47, 62, 61, 62, 59, 62, 61, 62, 55, 62, 61, 62, 59, 62, 61, 62, 63, 126, 125, 126, 123, 126, 125

Offset: 0

Author

Reinhard Zumkeller, Jul 15 2008

Keywords

• nonn
• hear
• look

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
• Reinhard Zumkeller, Logical Convolutions

Crossrefs

Cf. A003817, A000004, A142149, A086099, A142150, A001477, A089633.

Programs

Haskell

import Data.Bits (xor, (.|.))
a142151 :: Integer -> Integer
a142151 = foldl (.|.) 0 . zipWith xor [0..] . reverse . enumFromTo 1
-- Reinhard Zumkeller, Mar 31 2015

Julia

using IntegerSequences
A142151List(len) = [Bits("CIMP", n, n+1) for n in 0:len]
println(A142151List(69))  # Peter Luschny, Sep 25 2021

Maple

A142151 := n -> n + Bits:-Nor(n, n+1):
seq(A142151(n), n=0..69); # Peter Luschny, Sep 26 2019

Python

from functools import reduce
from operator import or_
def A142151(n): return 0 if n == 0 else reduce(or_,(k^n-k for k in range(n+1))) if n % 2 else (1 << n.bit_length()-1)-1 <<1 # Chai Wah Wu, Jun 30 2022

Formula

a(2*n) = 2*(A062383(n)-1);

A023416(a(n)) <= 1.