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.

A375001 Square array read by antidiagonals: T(n,k) is the position of the last requested element when the elements of the k-th composition (in standard order) are requested from a self-organizing list initialized to (1, 2, 3, ...), using the move-ahead(n) updating strategy; n >= 0, k >= 1.

Original entry on oeis.org

1, 2, 1, 1, 2, 1, 3, 1, 2, 1, 1, 3, 1, 2, 1, 2, 2, 3, 1, 2, 1, 1, 2, 2, 3, 1, 2, 1, 4, 1, 2, 2, 3, 1, 2, 1, 1, 4, 1, 2, 2, 3, 1, 2, 1, 2, 1, 4, 1, 2, 2, 3, 1, 2, 1, 1, 1, 2, 4, 1, 2, 2, 3, 1, 2, 1, 3, 1, 1, 2, 4, 1, 2, 2, 3, 1, 2, 1, 1, 3, 1, 1, 2, 4, 1, 2, 2, 3, 1, 2, 1
Offset: 0

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Author

Pontus von Brömssen, Jul 27 2024

Keywords

Comments

See A374996 for details.

Examples

			Array begins:
  n\k| 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15
  ---+--------------------------------------------
   0 | 1  2  1  3  1  2  1  4  1  2  1  3  1  2  1
   1 | 1  2  1  3  2  2  1  4  1  1  1  3  2  2  1
   2 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
   3 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
   4 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
   5 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
   6 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
   7 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
   8 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
   9 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
  10 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
  11 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
  12 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
  13 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
  14 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
  15 | 1  2  1  3  2  2  1  4  2  1  1  3  2  2  1
		

Crossrefs

Formula

T(0,k) = A007814(k) + 1.
T(1,k) = A374998(k).
T(n,k) = A374997(k) if n >= A333766(k)-1.
T(n,k) = A374996(n,k) - A374996(n,A025480(k-1)).
Sum_{j=1..m} T(n,k*2^j+2^(j-1)) = m*(m+1)/2 if m >= A333766(k). 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.