A059942 A059941 translated from binary to decimal.

1, 1, 3, 2, 2, 3, 7, 4, 5, 4, 4, 5, 4, 7, 15, 8, 9, 8, 9, 10, 9, 8, 8, 9, 10, 9, 8, 9, 8, 15, 31, 16, 17, 16, 19, 16, 17, 16, 17, 18, 21, 16, 17, 18, 17, 16, 16, 17, 18, 17, 16, 21, 18, 17, 16, 17, 16, 19, 16, 17, 16, 31, 63, 32, 33, 32, 35, 32, 33, 32, 35, 36, 33, 32, 35, 32, 33, 32

Offset

1,3

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Formula

a(n) =A059943(n)/2

Example

a(35)=19 since A059941(35)=10011.

Mathematica

a[n_] := (id = Drop[ IntegerDigits[n+1, 2], 1]+1; an = {}; Do[ PrependTo[an, If[Take[id, k] == Take[id, -k], 1, 0]], {k, 1, Length[id]}]; FromDigits[an, 2]); Table[a[n], {n, 1, 78}](* Jean-François Alcover, Nov 21 2011 *)

Prog

(Haskell)
import Data.List (inits, tails)
a059942 n = a059942_list !! (n-1)
a059942_list = map (foldr (\d v -> v * 2 + d) 0) $ f a030341_tabf where
   f (xs:xss)
     | 0 `elem` xs = f xss
     | otherwise = map fromEnum (zipWith (==)
                   (tail $ inits xs) (reverse $ init $ tails xs)) : f xss
-- Reinhard Zumkeller, Apr 03 2014

Crossrefs

Sequence in context: A361565 A334592 A248756 * A032450 A376274 A046460

Adjacent sequences: A059939 A059940 A059941 * A059943 A059944 A059945

Keyword

base,nonn

Author

Henry Bottomley, Feb 14 2001

Extensions

Offset fixed by Reinhard Zumkeller, Apr 03 2014

Status

approved