login
Working in binary, write n followed by 0 then n-reversed (including leading zeros); show result in base 10.
4

%I #23 Dec 03 2015 13:17:43

%S 0,5,17,27,65,85,99,119,257,297,325,365,387,427,455,495,1025,1105,

%T 1161,1241,1285,1365,1421,1501,1539,1619,1675,1755,1799,1879,1935,

%U 2015,4097,4257,4369,4529,4617,4777,4889,5049,5125,5285,5397,5557,5645,5805,5917,6077,6147,6307,6419,6579,6667,6827,6939,7099,7175

%N Working in binary, write n followed by 0 then n-reversed (including leading zeros); show result in base 10.

%C a(n) = A264619(n) - A062383(n); n>0: A070939(a(n)) = 2*A070939(n)+1; A000120(a(n)) = 2*A000120(n); n>0: A023416(a(n)) = 2*A023416(n)+1. - _Reinhard Zumkeller_, Dec 01 2015

%H N. J. A. Sloane, <a href="/A264618/b264618.txt">Table of n, a(n) for n = 0..32767</a>

%e 0 -> 000 = 0,

%e 1 -> 101 = 5,

%e 10 -> 10001 = 17,

%e 11 -> 11011 = 27,

%e 100 -> 1000001 = 65,

%e ...

%t A264618[n_]:=FromDigits[Join[#, {0}, Reverse[#]], 2] &@IntegerDigits[n, 2] (* _JungHwan Min_, Dec 01 2015 *)

%o (Haskell)

%o a264618 n = foldr (\b v -> 2 * v + b) 0 $ (reverse bs ++ (0 : bs))

%o where bs = map fromIntegral $ a030308_row n

%o -- _Reinhard Zumkeller_, Dec 01 2015

%Y Cf. A006995, A048701 (n followed by n-reversed), A264619.

%Y First differences: A265028.

%Y Cf. A007088, A030308, A000120, A023416, A062383, A070939.

%K nonn,base

%O 0,2

%A _N. J. A. Sloane_, Nov 30 2015