A059942 - OEIS

%I #9 Apr 03 2014 03:46:12

%S 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,

%T 16,17,16,19,16,17,16,17,18,21,16,17,18,17,16,16,17,18,17,16,21,18,17,

%U 16,17,16,19,16,17,16,31,63,32,33,32,35,32,33,32,35,36,33,32,35,32,33,32

%N A059941 translated from binary to decimal.

%H Reinhard Zumkeller, <a href="/A059942/b059942.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) =A059943(n)/2

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

%t 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 *)

%o (Haskell)

%o import Data.List (inits, tails)

%o a059942 n = a059942_list !! (n-1)

%o a059942_list = map (foldr (\d v -> v * 2 + d) 0) $ f a030341_tabf where

%o    f (xs:xss)

%o      | 0 `elem` xs = f xss

%o      | otherwise = map fromEnum (zipWith (==)

%o                    (tail $ inits xs) (reverse $ init $ tails xs)) : f xss

%o -- _Reinhard Zumkeller_, Apr 03 2014

%K base,nonn

%O 1,3

%A _Henry Bottomley_, Feb 14 2001

%E Offset fixed by _Reinhard Zumkeller_, Apr 03 2014