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.

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A346737 Number of configurations of the 5 X 3 variant of the sliding block 15-puzzle that require a minimum of n moves to be reached, starting with the empty square in one of the corners.

Original entry on oeis.org

1, 2, 4, 9, 21, 42, 89, 164, 349, 644, 1349, 2473, 5109, 9110, 18489, 32321, 64962, 112445, 223153, 378761, 740095, 1231589, 2364342, 3847629, 7246578, 11506172, 21233764, 32854049, 59293970, 89146163, 157015152, 228894783, 392648931, 553489877, 922382155
Offset: 0

Views

Author

Ben Whitmore, Jul 31 2021

Keywords

Comments

This sequence was originally computed by Richard Korf, but the full sequence was not included in his paper. It was later re-computed by Tomas Rokicki.

Examples

			Starting from the solved configuration
   1  2  3  4  5
   6  7  8  9 10
  11 12 13 14
the unique configuration requiring 84 moves is
   5  4  3  2  1
  10  9  8  7  6
     14 13 12 11
		

Crossrefs

Programs

A090377 Number of configurations that require a minimum of n moves to be reached, starting with the empty square in one of the corners of an infinitely large extension of Sam Loyd's sliding block 15-puzzle.

Original entry on oeis.org

1, 2, 4, 10, 26, 66, 173, 456, 1230, 3318, 9066, 24768, 68304, 188370, 523083, 1452560, 4054708, 11318926
Offset: 0

Views

Author

Hugo Pfoertner, Nov 27 2003

Keywords

Comments

The first n terms of this sequence coincide with the first n terms of the corresponding sequences for n X n sliding block puzzles (see Cross-references).

Crossrefs

Cf. A089473 (3 X 3 puzzle), A089484 (4 X 4), A090031 (5 X 5), A090032 (6 X 6).

Programs

  • Python
    # uses alst(), swap() in A089473
    nn = 13
    start = "".join([chr(i) for i in range(45, 45+(nn+1)**2)]) # chr(45) is "-"
    print(alst(start, (nn+1, nn+1), maxd=nn)) # Michael S. Branicky, Jan 02 2021

Extensions

a(10)-a(17) from Michael S. Branicky, Dec 28 2020
Previous Showing 11-12 of 12 results.