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.

A375000 Position of the last requested element when the elements of the n-th composition (in standard order) are requested from a self-organizing list initialized to (1, 2, 3, ...), where a requested element at position i is moved to position floor((i+1)/2).

Original entry on oeis.org

1, 2, 1, 3, 2, 2, 1, 4, 1, 1, 1, 3, 2, 2, 1, 5, 1, 3, 1, 3, 2, 2, 1, 4, 1, 1, 1, 3, 2, 2, 1, 6, 1, 3, 1, 2, 1, 3, 1, 4, 3, 1, 1, 3, 2, 2, 1, 5, 1, 3, 1, 3, 2, 2, 1, 4, 1, 1, 1, 3, 2, 2, 1, 7, 1, 2, 1, 4, 1, 3, 1, 4, 2, 2, 1, 2, 1, 3, 1, 5, 3, 1, 2, 3, 2, 2, 1
Offset: 1

Views

Author

Pontus von Brömssen, Jul 27 2024

Keywords

Comments

See A374995 for details.

Crossrefs

Analogous sequences for other updating strategies: A374997, A374998, A374999.
Cf. A025480, A066099 (compositions in standard order), A333766, A374995.

Formula

a(n) = A374995(n) - A374995(A025480(n-1)).
Sum_{j=1..m} a(n*2^j+2^(j-1)) = m*(m+1)/2 if m >= A333766(n). This is a consequence of the fact that the first m positions of the list are occupied by the elements 1, ..., m, as long as no element larger than m has been requested so far.