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 1-3 of 3 results.

A181230 Square array T(m,n) giving the number of m X n (0,1)-matrices with pairwise distinct rows and pairwise distinct columns.

Original entry on oeis.org

2, 2, 2, 0, 10, 0, 0, 24, 24, 0, 0, 24, 264, 24, 0, 0, 0, 1608, 1608, 0, 0, 0, 0, 6720, 33864, 6720, 0, 0, 0, 0, 20160, 483840, 483840, 20160, 0, 0, 0, 0, 40320, 5644800, 19158720, 5644800, 40320, 0, 0, 0, 0, 40320, 57415680, 595506240, 595506240, 57415680, 40320
Offset: 1

Views

Author

R. H. Hardin, Oct 10 2010

Keywords

Examples

			Table starts
.2..2.....0...........0...............0..................0
.2.10....24..........24...............0..................0
.0.24...264........1608............6720..............20160
.0.24..1608.......33864..........483840............5644800
.0..0..6720......483840........19158720..........595506240
.0..0.20160.....5644800.......595506240........44680224960
.0..0.40320....57415680.....16388749440......2881362718080
.0..0.40320...518676480....418910083200....172145618789760
.0..0.....0..4151347200..10136835072000...9841604944066560
.0..0.....0.29059430400.233811422208000.546156941728204800
		

Crossrefs

Cf. A088310 (diagonal), A181231, A181232, A181233 (subdiagonals).
Binary matrices with distinct rows and columns, various versions: A059202, A088309, A088310, A088616, A089673, A089674, A093466, A094000, A094223, A116532, A116539, A181230, A259763

Formula

T(m,n) = Sum_{i=0..n} Sum_{j=0..m} stirling1(n,i) * stirling1(m,j) * 2^(i*j) = n! * Sum_{j=0..m} stirling1(m,j) * binomial(2^j,n) = m! * Sum_{i=0..n} stirling1(n,i) * binomial(2^i,m). - Max Alekseyev, Jun 18 2016
T(m,n) = A059084(m,n) * n!.

A181232 Number of n X (n+2) binary matrices with all rows unique and all columns unique.

Original entry on oeis.org

0, 24, 6720, 5644800, 16388749440, 172145618789760, 6709378999665162240, 988932080423985278515200, 559938250258499272920457420800, 1233183626500802426354472388092518400, 10663689261713618730124837637890877517004800
Offset: 1

Views

Author

R. H. Hardin, Oct 10 2010

Keywords

Crossrefs

Second subdiagonal of A181230.

Formula

a(n) = A181230(n,n+2).

A181233 Number of nX(n+3) binary matrices with all rows unique and all columns unique.

Original entry on oeis.org

0, 0, 20160, 57415680, 418910083200, 9841604944066560, 811677284745084979200, 246193686664597924471296000, 282802656455710907157732271104000, 1254507391643066981024665558462201036800
Offset: 1

Views

Author

R. H. Hardin Oct 10 2010

Keywords

Crossrefs

Third subdiagonal of A181230.

Formula

a(n) = A181230(n,n+3).

Extensions

More terms from Max Alekseyev, Jun 18 2016
Showing 1-3 of 3 results.