A182248 a(0)=0, a(n) = (a(n-1) OR n) + n.

0, 2, 4, 10, 18, 28, 36, 46, 54, 72, 84, 106, 122, 140, 156, 174, 206, 240, 260, 298, 338, 364, 404, 430, 470, 504, 532, 570, 602, 636, 668, 702, 734, 800, 836, 906, 978, 1052, 1124, 1166, 1238, 1320, 1364, 1450, 1498, 1580

Offset: 0

Author

Alex Ratushnyak, Apr 20 2012

Keywords

• base
• nonn

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
• Eric Weisstein's World of Mathematics, OR
• Wikipedia, Bitwise operation OR

Programs

Haskell

import Data.Bits ((.|.))
a182248 n = a182248_list !! n
a182248_list = map fst $ iterate f (0,1) where
   f (y,x) = ((x .|. y) + x, x + 1) :: (Integer,Integer)
-- Reinhard Zumkeller, Apr 23 2012

Mathematica

nxt[{n_,a_}]:={n+1,BitOr[a,n+1]+n+1}; NestList[nxt,{0,0},50][[All,2]] (* Harvey P. Dale, Jun 01 2020 *)

Maxima

load(functs)$
A182248[0]:0$
A182248[n]:=logor(a[n-1],n) + n$
makelist(A182248[n],n,0,30); /* Martin Ettl, Nov 01 2012 */

Python

a=0
for i in range(1,51):
    print(a, end=',')
    a |= i
    a += i

Formula

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