A182243 a(0)=0, a(n) = (a(n-1) AND n) + n.

0, 1, 2, 5, 8, 5, 10, 9, 16, 9, 18, 13, 24, 21, 18, 17, 32, 17, 34, 21, 40, 21, 42, 25, 48, 41, 34, 29, 56, 53, 50, 49, 64, 33, 66, 37, 72, 37, 74, 41, 80, 41, 82, 45, 88, 53, 82, 49, 96, 81, 66, 53, 104, 85, 74, 57, 112, 105, 98, 93, 88, 85, 82, 81, 128, 65

Offset: 0

Author

Alex Ratushnyak, Apr 20 2012

Keywords

• nonn
• base
• look

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 0..8192=2^13
• Eric Weisstein's World of Mathematics, AND
• Wikipedia, Bitwise operation AND

Crossrefs

Cf. A182242.

Programs

Haskell

import Data.Bits ((.&.))
a182243 n = a182243_list !! n
a182243_list = map fst $ iterate f (0,1) where
   f (y,x) = ((x .&. y) + x, x + 1) :: (Integer,Integer)
-- Reinhard Zumkeller, Apr 23 2012

Mathematica

Join[{t = 0}, Table[t = BitAnd[t, n] + n, {n, 100}]] (* T. D. Noe, Apr 21 2012 *)

Python

a=0
for i in range(1,511):
    print(a, end=',')
    a &= i
    a += i

Formula

a(0) = 0, a(n) = (a(n-1) AND n) + n, where AND is the bitwise logical AND operator.