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.

Showing 1-5 of 5 results.

A316966 Same as A316671, except numbering of the squares starts at 0 rather than 1.

Original entry on oeis.org

0, 4, 3, 11, 10, 22, 21, 37, 36, 56, 55, 79, 78, 106, 105, 137, 136, 172, 171, 211, 210, 254, 253, 301, 300, 352, 351, 407, 406, 466, 465, 529, 528, 596, 595, 667, 666, 742, 741, 821, 820, 904, 903, 991, 990, 1082, 1081, 1177, 1176, 1276, 1275, 1379, 1378
Offset: 0

Views

Author

Daniël Karssen, Jul 17 2018

Keywords

Comments

See A316671 for further information.

Crossrefs

Cf. A316671.
Cf. A128918: it is provided by a(-n-1).

Programs

  • Mathematica
    Table[1 + (n + 2) (n - (-1)^n)/2, {n, 0, 60}] (* Bruno Berselli, Jul 19 2018 *)
  • PARI
    concat(0, Vec(x*(4 - x + x^3) / ((1 - x)^3*(1 + x)^2) + O(x^40))) \\ Colin Barker, Jul 19 2018

Formula

a(n) = A316671(n+1) - 1.
From Colin Barker, Jul 19 2018: (Start)
G.f.: x*(4 - x + x^3) / ((1 - x)^3*(1 + x)^2).
a(n) = a(n-1) + 2*a(n-2) - 2*a(n-3) - a(n-4) + a(n-5) for n>4. (End)
a(n) = 1 + (n + 2)*(n - (-1)^n)/2. - Bruno Berselli, Jul 19 2018

A316884 Squares visited by moving diagonally one square on a spirally numbered board and moving to the lowest available unvisited square at each step.

Original entry on oeis.org

1, 3, 11, 9, 23, 7, 19, 5, 15, 33, 13, 29, 53, 27, 25, 47, 77, 45, 21, 41, 69, 39, 17, 35, 61, 95, 59, 31, 55, 87, 127, 85, 51, 49, 79, 117, 163, 115, 75, 43, 71, 107, 151, 105, 67, 37, 63, 97, 139, 189, 137, 93, 57, 89, 129, 177, 233, 175, 125, 83, 81, 119
Offset: 1

Views

Author

Daniël Karssen, Jul 15 2018

Keywords

Comments

Board is numbered with the square spiral:
.
17--16--15--14--13
| |
18 5---4---3 12 .
| | | |
19 6 1---2 11 .
| | |
20 7---8---9--10 .
|
21--22--23--24--25--26

Crossrefs

A316668 Squares visited by king moves on a diagonally numbered board and moving to the lowest available unvisited square at each step.

Original entry on oeis.org

1, 2, 3, 5, 4, 7, 8, 9, 6, 10, 14, 13, 12, 11, 16, 17, 18, 19, 20, 15, 21, 27, 26, 25, 24, 23, 22, 29, 30, 31, 32, 33, 34, 35, 28, 36, 44, 43, 42, 41, 40, 39, 38, 37, 46, 47, 48, 49, 50, 51, 52, 53, 54, 45, 55, 65, 64, 63, 62, 61, 60, 59, 58, 57, 56, 67, 68
Offset: 1

Views

Author

Daniël Karssen, Jul 15 2018

Keywords

Comments

Board is numbered as follows:
1 2 4 7 11 16 .
3 5 8 12 17 .
6 9 13 18 .
10 14 19 .
15 20 .
21 .
.
Same as A316588 but with king move instead of knight move.

Crossrefs

A316669 Squares visited by queen moves on a diagonally numbered board and moving to the lowest available unvisited square at each step.

Original entry on oeis.org

1, 2, 3, 5, 4, 6, 9, 7, 8, 10, 14, 11, 12, 13, 15, 20, 16, 17, 18, 19, 21, 27, 22, 23, 24, 25, 26, 28, 35, 29, 30, 31, 32, 33, 34, 36, 44, 37, 38, 39, 40, 41, 42, 43, 45, 54, 46, 47, 48, 49, 50, 51, 52, 53, 55, 65, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, 77
Offset: 1

Views

Author

Daniël Karssen, Jul 15 2018

Keywords

Comments

Board is numbered as follows:
1 2 4 7 11 16 .
3 5 8 12 17 .
6 9 13 18 .
10 14 19 .
15 20 .
21 .
.
Same as A316588 but with queen move instead of knight move.

Crossrefs

A316670 Squares visited by bishop moves on a diagonally numbered board and moving to the lowest available unvisited square at each step.

Original entry on oeis.org

1, 5, 4, 6, 14, 11, 12, 13, 15, 27, 22, 23, 24, 25, 26, 28, 44, 37, 38, 39, 40, 41, 42, 43, 45, 65, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, 90, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 91, 119, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117
Offset: 1

Views

Author

Daniël Karssen, Jul 15 2018

Keywords

Comments

Board is numbered as follows:
1 2 4 7 11 16 .
3 5 8 12 17 .
6 9 13 18 .
10 14 19 .
15 20 .
21 .
.
Same as A316588 but with bishop move instead of knight move.

Crossrefs

Showing 1-5 of 5 results.