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 1-2 of 2 results.

A129352 Number parallelogram based on Pascal's triangle, read along diagonals.

Original entry on oeis.org

70, 35, 35, 15, 40, 15, 5, 30, 30, 5, 1, 16, 36, 16, 1, 5, 30, 30, 5, 15, 40, 15, 35, 35, 70
Offset: 0

Views

Author

Zerinvary Lajos, May 28 2007

Keywords

Examples

			Terms are the following square, read by diagonals:
  70, 35, 15,  5,  1
  35, 40, 30, 16,  5
  15, 30, 36, 30, 15
   5, 16, 30, 40, 35
   1,  5, 15, 35, 70
		

Crossrefs

Cf. A113899.

Programs

  • Maple
    with(combinat):T:=(n,i)->binomial(i,n)*binomial(8-i,4-n): for n from 0 to 4 do seq(T(n, i), i=0+n..8-4+n) od;

Extensions

Edited slightly by Charles R Greathouse IV, Oct 28 2009

A129536 Number parallelogram based on Pascal's triangle (and special mirror of central and multiply of diagonal).

Original entry on oeis.org

45, 9, 36, 1, 16, 28, 3, 21, 21, 6, 24, 15, 10, 25, 10, 15, 24, 6, 21, 21, 3, 28, 16, 1, 36, 9, 45
Offset: 0

Views

Author

Zerinvary Lajos, May 29 2007

Keywords

Comments

Sequence arrangement:
....................C(10,2)*C(0,0)
.............C(9,1)*C(1,1)...C(9,2)*C(1,0)
.....C(8,0)*C(2,2)...C(8,1)*C(2,1)...C(8,2)*C(2,0)
..............C(7,0)*C(3,2)...C(7,1)*C(3,1)...C(7,2)*C(3,0)
.....................C(6,0)*C(4,2)...C(6,1)*C(4,1)...C(6,2)*C(4,0)
.............................C(5,0)*C(5,2)...C(5,1)*C(5,1)...C(5,2)*C(5,0)
.....................................C(4,0)*C(6,2)...C(4,1)*C(6,1)...C(4,2)*C(6,0)
.............................................C(3,0)*C(7,2)...C(3,1)*C(7,1)...C(3,2)*C(7,0)
.....................................................C(2,0)*C(8,2)...C(2,1)*C(8,1)...C(2,2)*C(8,0)
.............................................................C(1,0)*C(9,2)...C(1,1)*C(9,1)
.....................................................................C(0,0)*C(10,2)
"m" matching: analog (permutations with exactly "m" fixed points.
if aabbbbbbbb (a twice letters b 8 times letters) permutations compared aaaaaaaaaa (a 10 times letters) then 45 * "2" matching.(sum 45)("2" matching: analog(permutations with exactly 2 fixed points.)
if compared bbbbbbbbbb (b 10 times letters then 45 * "8" matching.(sum 45)
("8" matching: analog (permutations with exactly 8 fixed points.).
If aabbbbbbbb (a 2 letters b 8 letters) permutations compared
aabbbbbbbb (a twice letters b 8 times letters)then 1 * "10"
matching),16 * "8" matching, 28 * "6" matching (sum 45)
If aabbbbbbbb (a 8 letters b 2 letters)permutations compared
aaaaaaaabb (a 8 times letters b twice letters)then 1 * "0"
matching),16 * "2" matching, 28 * "4" matching (sum 45)
all rows (sum 45)
etc...
matching equialent or analog "fixed points"
example:
arrangement relevant!
compared
letters..
times....
a...b
matching:..........0..1..2..3..4..5..6..7..8..9..10 0..10...................45.........................
.1..9.................9....36......................
.2..8..............1.....16....28..................
.3..7.................3....21.....21................
.4..6....................6....24....15............
.5..5......................10....25.....10.........
.6..4.........................15....24.....6........
.7..3.............................21....21.....3....
.8..2................................28....16......1
.9..1...................................36.....9....
10..0......................................45.......
matching:...........0..1..2..3..4..5..6..7..8..9..10
The Maple code produces this:
45, 36, 28, 21, 15, 10, 6, 3, 1
9, 16, 21, 24, 25, 24, 21, 16, 9
1, 3, 6, 10, 15, 21, 28, 36, 45
This is the table rotated right by Pi/4.

Crossrefs

Cf. A113899.

Programs

  • Maple
    with(combinat):T:=(n,i)->binomial(i,n)*binomial(10-i,2-n): for n from 0 to 2 do seq(T(n, i), i=0+n..10-2+n) od;

Extensions

Edited by Charles R Greathouse IV, Oct 28 2009
Showing 1-2 of 2 results.