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.

A105023 a(n) = A102370(n) - n. Or, 2*A103185(n).

Original entry on oeis.org

0, 2, 4, 2, 0, 10, 4, 2, 0, 2, 4, 2, 16, 10, 4, 2, 0, 2, 4, 2, 0, 10, 4, 2, 0, 2, 4, 34, 16, 10, 4, 2, 0, 2, 4, 2, 0, 10, 4, 2, 0, 2, 4, 2, 16, 10, 4, 2, 0, 2, 4, 2, 0, 10, 4, 2, 0, 2, 68, 34, 16, 10, 4, 2, 0, 2, 4, 2, 0, 10, 4, 2, 0, 2, 4, 2, 16, 10, 4, 2, 0, 2, 4, 2, 0, 10, 4, 2, 0, 2, 4, 34, 16, 10, 4
Offset: 0

Views

Author

N. J. A. Sloane, Apr 03 2005

Keywords

Comments

When written in base 2 as a right justified table, columns have periods 1, 2, 4, 8, ... - Philippe Deléham, Apr 21 2005

Examples

			Has a natural decomposition into blocks: 0; 2; 4, 2, 0; 10, 4, 2, 0, 2, 4, 2; 16, 10, 4, 2, 0, 2, 4, 2, 0, 10, 4, 2, 0, 2, 4; 34, 16, 10, 4, ... where the leading term in each block is given by A105024.
		

Crossrefs

Programs

  • Maple
    s:= proc (n) local t1, l; t1 := 0; for l to n do if `mod`(n+l,2^l) = 0 then t1 := t1+2^l end if end do; t1 end proc;

Formula

a(n) = Sum_{ k >= 1 such that n + k == 0 mod 2^k } 2^k.