cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A078823 Sum of distinct binary numbers contained as substrings in binary representation of n.

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%I A078823 #13 Jul 31 2022 07:47:28
%S A078823 0,1,3,4,7,8,12,11,15,16,18,22,28,30,33,26,31,32,34,38,42,39,50,52,60,
%T A078823 62,66,68,77,80,78,57,63,64,66,70,70,76,82,84,90,92,81,96,110,108,118,
%U A078823 114,124,126,130,132,142,140,144,153,165,168,174,177,182,186,171,120
%N A078823 Sum of distinct binary numbers contained as substrings in binary representation of n.
%H A078823 Reinhard Zumkeller, <a href="/A078823/b078823.txt">Table of n, a(n) for n = 0..10000</a>
%F A078823 a(2^k-1) = 2^(k+1)-(k+2); a(2^k) = 2^(k+1)-1;
%F A078823 for k>0: a(2^k+1) = 2^(k+1);
%F A078823 a(2^k-1) = A078825(2^k-1), a(2^k) = A078825(2^k).
%e A078823 n=10: sum of the A078822(10)=5 binary numbers: a(10) = '0'+'1'+'10'+'101'+'1010' = 0+1+2+5+10 = 18.
%o A078823 (Haskell)
%o A078823 a078823 = sum . a119709_row  -- _Reinhard Zumkeller_, Aug 14 2013
%o A078823 (Python)
%o A078823 def a(n): return sum(set(((((2<<l)-1)<<i)&n)>>i for i in range(n.bit_length()) for l in range(n.bit_length()-i)))
%o A078823 print([a(n) for n in range(64)]) # _Michael S. Branicky_, Jul 28 2022
%Y A078823 Cf. A078822, A078825, A007088, A144623, A144624.
%K A078823 nonn,base
%O A078823 0,3
%A A078823 _Reinhard Zumkeller_, Dec 08 2002