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 1-4 of 4 results.

A181200 a(n) = 0!*1!*2!*...*(n-1)! *(n^2)! *(n*(n-1))^2 / 2*n!*(n+1)!*...*(2*n-1)!

Original entry on oeis.org

0, 4, 756, 1729728, 140229804000, 752239365180732000, 419014989521191873479589920, 34623595988556658225393154134784716800, 571228532851873223553288547443139274046846826752000
Offset: 1

Views

Author

R. H. Hardin Oct 10 2010

Keywords

Comments

(Empirical) Number of n X n matrices containing a defective permutation of 1..n*n in strictly increasing order rowwise and columnwise, with one permutation value omitted and one repeated (see example)
Diagonal of A181204

Examples

			Some solutions for 3X3
..2..3..5....1..2..5....1..2..6....1..3..4....1..3..4....1..2..4....1..3..5
..4..6..7....3..4..6....3..4..8....2..5..8....2..6..7....2..5..7....2..4..6
..5..8..9....4..7..9....6..7..9....4..6..9....5..7..9....3..6..9....6..7..8

Links

A181201 a(n) = 0!*1!*2!*(3*n)!*3*n*(n-1) / ((n)!*(n+1)!*(n+2)!).

Original entry on oeis.org

0, 30, 756, 16632, 360360, 7876440, 174594420, 3926434512, 89492111280, 2064420294300, 48134517631200, 1133012491934400, 26895067957892160, 643240375326254160, 15487976684184750900, 375182135475713517600
Offset: 1

Views

Author

R. H. Hardin, Oct 10 2010

Keywords

Comments

(Empirical) Number of n X 3 matrices containing a defective permutation of 1..3*n in strictly increasing order rowwise and columnwise, with one permutation value omitted and one repeated (see example).
Column 3 of A181204.

Examples

			Some solutions for 4 X 3
..1..3..4....1..4..6....1..4..6....1..2..8....1..2..7....1..2..8....1..2..3
..2..6..9....2..5..7....2..7..9....3..4..9....2..5..9....2..5..9....2..6..7
..7..8.10....3..9.11....3..8.11....5..7.11....3..8.11....3..6.11....5..8..9
.10.11.12....5.10.12....7.10.12....6..9.12....6.10.12....7.10.12...10.11.12

Links

Crossrefs

Cf. A181204.

A181202 a(n)=0!*1!*2!*3!*(4*n)!*6*n*(n-1) / ((n)!*(n+1)!*(n+2)!*(n+3)!).

Original entry on oeis.org

0, 168, 16632, 1729728, 199536480, 25241364720, 3445446284280, 500598983364480, 76591644454765440, 12237255920840932800, 2028351316862121451200, 346968438887939861076480, 60995474427232155123331200
Offset: 1

Views

Author

R. H. Hardin Oct 10 2010

Keywords

Comments

(Empirical) Number of nX4 matrices containing a defective permutation of 1..4*n in strictly increasing order rowwise and columnwise, with one permutation value omitted and one repeated (see example)
Column 4 of A181204

Examples

			Some solutions for 2X4
..1..3..4..5....1..2..4..5....2..4..5..7....1..2..3..4....1..3..4..6
..2..5..7..8....3..5..7..8....3..6..7..8....4..5..6..8....5..6..7..8

Links

A181203 a(n)=0!*1!*2!*3!*4!*(5*n)!*10*n*(n-1) / ((n)!*(n+1)!*(n+2)!*(n+3)!*(n+4)!).

Original entry on oeis.org

0, 840, 360360, 199536480, 140229804000, 118949931243000, 117015012361447200, 129624266420759510400, 158211402715245473193600, 209298196564031904834960000, 296336346592302886974184080000
Offset: 1

Views

Author

R. H. Hardin Oct 10 2010

Keywords

Comments

(Empirical) Number of nX5 matrices containing a defective permutation of 1..5*n in strictly increasing order rowwise and columnwise, with one permutation value omitted and one repeated (see example)
Column 5 of A181204

Examples

			Some solutions for 2X5
..1..4..5..6..8....1..2..4..7..9....1..3..5..8..9....1..2..5..6..8
..3..5..7..9.10....5..6..8..9.10....4..6..7..9.10....3..4..8..9.10

Links

Showing 1-4 of 4 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.