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.

A260022 A bisection of A006921.

Original entry on oeis.org

1, 3, 7, 13, 29, 55, 115, 209, 465, 883, 1847, 3357, 7437, 14087, 29443, 53505, 119041, 226051, 472839, 859405, 1903901, 3606327, 7537523, 13697489, 30474449, 57868403, 121045047, 220004381, 487391245, 923205639, 1929576451, 3506503681, 7801470977, 14814478339, 30987976711, 56321966093
Offset: 0

Views

Author

N. J. A. Sloane, Jul 14 2015

Keywords

Crossrefs

Programs

  • Haskell
    a260022 = a006921 . (* 2)  -- Reinhard Zumkeller, Jul 14 2015
    
  • Python
    def A260022(n): return sum(int(not r & ~(2*n-r))*2**(n-r) for r in range(n+1)) # Chai Wah Wu, Jun 20 2022

Formula

a(n) = A006921(2*n).