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A281313 Write n in Elias's delta code, interchange the 1's and 0's and convert it back to decimal.

%I A281313 #9 Mar 20 2025 14:41:24
%S A281313 0,7,6,11,10,9,8,63,62,61,60,59,58,57,56,111,110,109,108,107,106,105,
%T A281313 104,103,102,101,100,99,98,97,96,191,190,189,188,187,186,185,184,183,
%U A281313 182,181,180,179,178,177,176,175,174,173,172,171,170,169,168,167,166,165,164,163,162
%N A281313 Write n in Elias's delta code, interchange the 1's and 0's and convert it back to decimal.
%H A281313 Indranil Ghosh, <a href="/A281313/b281313.txt">Table of n, a(n) for n = 1..10000</a>
%e A281313 For n = 10, the Elias delta code for 10 is '11000010' and after interchanging the 0's and 1's it becomes '00111101'. Now, 111101_2 = 61_10. So, a(10) = 61.
%o A281313 (Python)
%o A281313 def a(n):
%o A281313     s=""
%o A281313     for i in A281150(n):
%o A281313         if i=="1":
%o A281313             s+="0"
%o A281313         else:
%o A281313             s+="1"
%o A281313     return int(s, 2)
%Y A281313 Cf. A035327, A054429 (n is converted to Elias gamma code, the 1's and 0's are interchanged and the code is converted back to decimal, for n>1), A281150.
%K A281313 nonn,base
%O A281313 1,2
%A A281313 _Indranil Ghosh_, Jan 19 2017