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.

Original entry on oeis.org

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, 62, 66, 68, 77, 80, 78, 57, 63, 64, 66, 70, 70, 76, 82, 84, 90, 92, 81, 96, 110, 108, 118, 114, 124, 126, 130, 132, 142, 140, 144, 153, 165, 168, 174, 177, 182, 186, 171, 120
Offset: 0

Views

Author

Reinhard Zumkeller, Dec 08 2002

Keywords

Examples

			n=10: sum of the A078822(10)=5 binary numbers: a(10) = '0'+'1'+'10'+'101'+'1010' = 0+1+2+5+10 = 18.
		

Crossrefs

Programs

  • Haskell
    a078823 = sum . a119709_row  -- Reinhard Zumkeller, Aug 14 2013
    
  • Python
    def a(n): return sum(set(((((2<>i for i in range(n.bit_length()) for l in range(n.bit_length()-i)))
    print([a(n) for n in range(64)]) # Michael S. Branicky, Jul 28 2022

Formula

a(2^k-1) = 2^(k+1)-(k+2); a(2^k) = 2^(k+1)-1;
for k>0: a(2^k+1) = 2^(k+1);
a(2^k-1) = A078825(2^k-1), a(2^k) = A078825(2^k).