A063565 - OEIS

%I #12 Jun 20 2015 11:45:24

%S 10,4,1,5,2,8,4,15,3,12,10,40,7,17,18,21,4,27,30,13,11,18,43,41,10,8,

%T 18,15,7,32,22,17,5,25,27,25,16,30,14,42,12,22,19,22,18,28,42,31,11,

%U 32,52,9,19,16,25,16,8,20,33,33,23,58,18,14,6,16,46,24,15,34,29,21,17,30

%N Smallest positive number k such that 2^k contains n.

%H Chai Wah Wu, <a href="/A063565/b063565.txt">Table of n, a(n) for n = 0..10000</a>

%H Popular Computing (Calabasas, CA), <a href="/A094776/a094776.jpg">Two Tables</a>, Vol. 1, (No. 9, Dec 1973), page PC9-16.

%e a(7) = 15 because 2^15 = 32768.

%t a = {}; Do[k = 1; While[ StringPosition[ ToString[2^k], ToString[n] ] == {}, k++ ]; a = Append[a, k], {n, 0, 50} ]; a

%o (Python)

%o def A063565(n):

%o ....s, k, k2 = str(n), 1, 2

%o ....while True:

%o ........if s in str(k2):

%o ............return k

%o ........k += 1

%o ........k2 *= 2 # _Chai Wah Wu_, Jun 20 2015

%Y Apart from initial term, a duplicate of A030000.

%Y Cf. A006889, A131535, A131536, A259089, A063565, A259091, A259092.

%K base,nonn

%O 0,1

%A _Robert G. Wilson v_, Aug 10 2001

%E More terms from _Hans Havermann_