Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #16 Apr 04 2013 14:35:47
%S 1,5,1,7,17,37,41,85,11,23,73,149,1,55,169,341,65,133,137,277,145,293,
%T 11,199,161,325,329,661,337,677,227,455,43,29,265,533,91,61,553,1109,
%U 289,581,65,391,593,1189,1193,2389,107,215,649,1301,73,439,1321,2645
%N Double 1's in binary representations of 2*n-1, converting to decimal and dividing by maximal possible power of 3.
%H Peter J. C. Moses, <a href="/A224139/b224139.txt">Table of n, a(n) for n = 1..10000</a>
%e Let n=6, 2*n-1=11 which in binary 1011. Number with double 1's is 1101111 which in decimal 111. Thus a(6)=111/3=37.
%t Map[#/3^IntegerExponent[#,3]&[FromDigits[Flatten[IntegerDigits[2#-1,2]/.{1->{1,1}}],2]]&,Range[100]] (* _Peter J. C. Moses_, Mar 31 2013 *)
%K nonn,base
%O 1,2
%A _Vladimir Shevelev_, Mar 31 2013