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.

User: Awani Kumar

Awani Kumar's wiki page.

Awani Kumar has authored 11 sequences. Here are the ten most recent ones:

A331483 Number of near-magic (only short lines are magic) knight's tours on a 6 X 2n board.

Original entry on oeis.org

0, 0, 0, 42, 28, 2056
Offset: 1

Author

Awani Kumar, Jan 18 2020

Keywords

Comments

A semi-magic knight's tour is a tour that adds to a constant sum in every line in one direction, but not in every line in the perpendicular direction. A near-magic tour is a special type of semi-magic tour in which the non-magic direction has the lines add to the magic constant and two other values. Such tours are of interest on boards where magic tours don't exist.

Examples

			Example of 6 X 10 near-magic knight's tour. All short lines add to 183 and the long lines add to the magic constant 305 and 305 +- 6.
29 50 53 14 27 16 55 38 03 20
52 13 28 17 54 25 02 19 56 39
49 30 51 26 15 18 37 60 21 04
12 09 32 45 36 43 24 01 40 57
31 48 11 34 07 46 59 42 05 22
10 33 08 47 44 35 06 23 58 41
		

Crossrefs

A330758 Number of quasi-magic (only short lines are magic) knight's tours on a 6 X 2n board.

Original entry on oeis.org

0, 0, 0, 28, 34, 484
Offset: 1

Author

Awani Kumar, Jan 18 2020

Keywords

Comments

A quasi-magic tour is a special type of semi-magic tour in which the non-magic lines add to only two different values. Such tours are of interest on boards where magic tours don't exist.

Examples

			Example of 6 X 10 quasi-magic knight's tour. All short lines add to 183 and the long lines add to either 299 or 311, that is, 305 +- 6.
01 20 59 42 17 26 29 44 15 46
60 41 02 19 28 43 16 47 30 13
21 04 39 58 25 18 27 14 45 48
40 57 22 03 54 51 08 33 12 31
05 38 55 24 07 36 53 10 49 34
56 23 06 37 52 09 50 35 32 11
		

Crossrefs

A330611 Number of near-magic (only long lines are magic) knight's tours on a 4 X 2n board.

Original entry on oeis.org

0, 0, 2, 16, 22, 112, 330, 1304, 6322
Offset: 1

Author

Awani Kumar, Dec 20 2019

Keywords

Comments

A semi-magic knight's tour is a tour that adds to a constant sum in every line in one direction, but not in every line in the perpendicular direction. A near-magic tour is a special type of semi-magic tour in which the non-magic direction has the lines add to the magic constant and two other values. Such tours are of interest on boards where magic tours don't exist.

Examples

			Example of 4 x 14 near-magic knight's tour. All long lines add to 399 and the short lines add to the magic constant 114 and 114 +- 4.
   1 54 25 32  5 52 23 48  9 38 11 40 17 44
  28 31  4 53 24 33  6 37 20 47 18 43 14 41
  55  2 29 26 51 22 35  8 49 10 39 12 45 16
  30 27 56  3 34  7 50 21 36 19 46 15 42 13
		

Crossrefs

A330610 Number of near-magic (only short lines are magic) knight's tours on a 4 X 2n board.

Original entry on oeis.org

0, 0, 0, 4, 16, 72, 244, 1012, 3976, 18440, 81252, 388188, 1800728, 8769964
Offset: 1

Author

Awani Kumar, Dec 20 2019

Keywords

Comments

A semi-magic knight's tour is a tour that adds to a constant sum in every line in one direction, but not in every line in the perpendicular direction. A near-magic tour is a special type of semi-magic tour in which the non-magic direction has the lines add to the magic constant and two other values. Such tours are of interest on boards where magic tours don't exist.

Examples

			Example of 4 X 14 near-magic knight's tour. All short lines add to 114 and the long lines add to the magic constant 399 and 399 +- 4.
   1 54 25 32  5 36 23 50 19 44  9 40 15 46
  28 31  4 53 24 51 20 35  8 39 14 45 10 41
  55  2 29 26 33  6 37 22 49 18 43 12 47 16
  30 27 56  3 52 21 34  7 38 13 48 17 42 11
		

Crossrefs

A330529 Number of quasi-magic (only long lines are magic) knight's tours on a 4 X 2n board.

Original entry on oeis.org

0, 0, 4, 10, 30, 48, 170, 710, 2492
Offset: 1

Author

Awani Kumar, Dec 17 2019

Keywords

Comments

A quasi-magic tour is a special type of semi-magic tour in which the non-magic lines add to only two different values. Such tours are of interest on boards where magic tours don't exist.

Examples

			Example of 4 X 14 quasi-magic knight's tour. All long lines sum to 399 and the short lines sum to either 112 or 126.
   3 52 19 40  1 50 21 42 13 48 23 30 11 46
  18 39  2 51 20 41 14 49 22 29 12 47 24 31
  53  4 37 16 55  6 35 28 43  8 33 26 45 10
  38 17 54  5 36 15 56  7 34 27 44  9 32 25
		

Crossrefs

A329483 Number of quasi-magic (only short lines are magic) knight's tours on a 4 X 2n board.

Original entry on oeis.org

0, 0, 0, 4, 12, 28, 136, 488, 2624, 12420, 64120, 313584, 1675648, 8536072
Offset: 1

Author

Awani Kumar, Nov 14 2019

Keywords

Comments

A quasi-magic tour is a special type of semi-magic tour in which the non-magic lines add to only two different values. Such tours are of interest on boards where magic tours don't exist.

Examples

			Example of 4 X 14 quasi-magic knight's tour. All short lines sum to 114 and the long lines sum to 397 and 401, that is, 399 +- 2.
   3 56 25 32  5 52 21 36  9 48 11 40 15 44
  26 29  4 53 24 33  8 49 20 37 18 43 12 41
  55  2 31 28 51  6 35 22 47 10 39 14 45 16
  30 27 54  1 34 23 50  7 38 19 46 17 42 13
		

Crossrefs

A329370 Number of semi-magic (only long lines are magic) knight's tours on a 4 X 2n board.

Original entry on oeis.org

0, 0, 16, 136, 3102, 58356, 1092618
Offset: 1

Author

Awani Kumar, Nov 12 2019

Keywords

Examples

			Example 4 X 10 semi-magic knight's tour (only long lines are magic, Magic Constant is 205):
   1 22  3 40 17 34  9 30 13 36
   4 25 20 27  8 29 16 35 10 31
  21  2 23  6 39 18 33 12 37 14
  24  5 26 19 28  7 38 15 32 11
		

Crossrefs

Cf. A328816.

A328872 Number of semi-magic (only short lines are magic) knight's tours on a 6 X n board.

Original entry on oeis.org

0, 0, 0, 0, 0, 88, 288, 1880, 9994, 93718, 660282, 4310970
Offset: 1

Author

Awani Kumar, Oct 29 2019

Keywords

Examples

			Example 6 X 7 semi-magic knight's tour (only short lines are magic):
    +----+----+----+----+----+----+----+
    |  1 | 28 |  3 |  6 | 31 | 26 | 23 |
    +----+----+----+----+----+----+----+
    |  4 |  7 | 30 | 27 | 24 | 19 | 32 |
    +----+----+----+----+----+----+----+
    | 29 |  2 |  5 |  8 | 33 | 22 | 25 |
    +----+----+----+----+----+----+----+
    | 14 | 41 | 38 | 35 | 20 | 11 | 18 |
    +----+----+----+----+----+----+----+
    | 39 | 36 | 13 | 16 |  9 | 34 | 21 |
    +----+----+----+----+----+----+----+
    | 42 | 15 | 40 | 37 | 12 | 17 | 10 |
    +----+----+----+----+----+----+----+
		

Crossrefs

Cf. A309273.

A328816 Number of semi-magic (only short lines are magic) knight's tours on a 4 X 2n board.

Original entry on oeis.org

0, 0, 0, 16, 104, 608, 3480, 19212, 213280, 587072, 3237456
Offset: 1

Author

Awani Kumar, Oct 28 2019

Keywords

Examples

			Example of a 4 X 10 semi-magic knight's tour (only the short lines are magic):
   +----+----+----+----+----+----+----+----+----+----+
   |  1 | 38 |  3 | 24 |  5 | 34 |  9 | 26 | 13 | 30 |
   +----+----+----+----+----+----+----+----+----+----+
   | 20 | 23 | 18 | 37 |  8 | 25 |  6 | 29 | 10 | 27 |
   +----+----+----+----+----+----+----+----+----+----+
   | 39 |  2 | 21 |  4 | 33 | 16 | 35 | 12 | 31 | 14 |
   +----+----+----+----+----+----+----+----+----+----+
   | 22 | 19 | 40 | 17 | 36 |  7 | 32 | 15 | 28 | 11 |
   +----+----+----+----+----+----+----+----+----+----+
		

Crossrefs

Formula

a(n) = A309273(2*n).

A309273 Number of semi-magic (only short lines are magic) knight's tours on a 4 X n board.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 9, 16, 38, 104, 267, 608, 1444, 3480, 8221, 19212, 45262, 213280, 250247, 587072, 1378912, 3237456
Offset: 1

Author

Awani Kumar, Jul 20 2019

Keywords

Examples

			Example 4 X 7 semi-magic knight's tour (only short lines are magic):
  +----+----+----+----+----+----+----+
  |  9 | 28 |  7 | 18 |  3 | 24 | 13 |
  +----+----+----+----+----+----+----+
  |  6 | 17 | 10 | 25 | 14 | 21 |  2 |
  +----+----+----+----+----+----+----+
  | 27 |  8 | 15 |  4 | 19 | 12 | 23 |
  +----+----+----+----+----+----+----+
  | 16 |  5 | 26 | 11 | 22 |  1 | 20 |
  +----+----+----+----+----+----+----+
.
Example 4 X 16 semi-magic knight's tour (only short lines are magic):
   1 62  3 36 29 38 19 58 25 44 17 56 23 52 15 54
  32 35 30 61  4 59 26 45 18 57 24 43 16 55 12 51
  63  2 33 28 37  6 39 20 47  8 41 22 49 10 53 14
  34 31 64  5 60 27 46  7 40 21 48  9 42 13 50 11
		

Crossrefs