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.

A322487 Number of (3*n) X n matrices with nonnegative integer entries and each column sum being 3 up to permutation of rows.

Original entry on oeis.org

1, 3, 31, 686, 27036, 1688360, 154703688, 19692332568, 3342458334775, 732812082630803, 202322386045180686, 68898094282978653925, 28443422251718020038049, 14029033632468285836567998, 8164217197799501761637725983, 5545466507405459243366712102466
Offset: 0

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Author

Andrew Howroyd, Dec 11 2018

Keywords

Comments

Also number of multiset partitions of [1,1,1,2,2,2,...,n,n,n] into nonempty multisets. - Marko Riedel, Nov 29 2022

Examples

			a(1) = 3 because up to permutations of rows there are 3 column vectors with sum 3: [1, 1, 1], [2, 1, 0] and [3, 0, 0].
		

Crossrefs

Row n=3 of A219727.

A358722 Triangle read by rows. Number T(n, k) of partitions of the multiset [1, 1, 1, 1, 2, 2, 2, 2, ..., n, n, n, n] into k nonempty submultisets, for 1 <= k <= 4n.

Original entry on oeis.org

1, 1, 2, 1, 1, 1, 12, 29, 32, 21, 10, 3, 1, 1, 62, 513, 1399, 1857, 1513, 855, 364, 119, 31, 6, 1, 1, 312, 8165, 55704, 155989, 231642, 215250, 139789, 68154, 26135, 8105, 2071, 435, 75, 10, 1, 1, 1562, 125121, 2076531, 12235869, 34100001, 53914814, 54898626, 39436580, 21332108, 9098469, 3160761, 914625, 223740, 46628, 8291, 1245, 155, 15, 1
Offset: 0

Views

Author

Marko Riedel, Nov 28 2022

Keywords

Comments

A generalization of ordinary Stirling set numbers to multisets that contain some m instances each of n elements, here we have m=4.

Examples

			The triangular array starts:
[0]: 1
[1]: 1,  2,   1,    1;
[2]: 1, 12,  29,   32,   21,   10,   3,   1;
[3]: 1, 62, 513, 1399, 1857, 1513, 855, 364, 119, 31, 6, 1;
		

References

  • F. Harary and E. Palmer, Graphical Enumeration, Academic Press, 1973.

Crossrefs

Cf. A008277, A358710, A358721, A358781 (row sums).

A358710 Triangle read by rows. Number T(n, k) of partitions of the multiset [1, 1, 2, 2, ..., n, n] into k nonempty submultisets, for 1 <= k <= 2n.

Original entry on oeis.org

1, 1, 1, 1, 4, 3, 1, 1, 13, 26, 19, 6, 1, 1, 40, 183, 259, 163, 55, 10, 1, 1, 121, 1190, 3115, 3373, 1896, 620, 125, 15, 1, 1, 364, 7443, 34891, 62240, 54774, 27610, 8706, 1795, 245, 21, 1, 1, 1093, 45626, 374059, 1072316, 1435175, 1063570, 485850, 146363, 30261, 4361, 434, 28, 1
Offset: 0

Views

Author

Marko Riedel, Nov 27 2022

Keywords

Comments

A generalization of ordinary Stirling set numbers to multisets that contain some m instances each of n elements, here we have m=2.

Examples

			The triangular array starts:
[0] 1;
[1] 1,   1;
[2] 1,   4,    3,     1;
[3] 1,  13,   26,    19,     6,     1;
[4] 1,  40,  183,   259,   163,    55,    10,    1;
[5] 1, 121, 1190,  3115,  3373,  1896,   620,  125,   15,   1;
[6] 1, 364, 7443, 34891, 62240, 54774, 27610, 8706, 1795, 245, 21, 1;
		

References

  • F. Harary and E. Palmer, Graphical Enumeration, Academic Press, 1973.

Crossrefs

Cf. A008277, A020555 (row sums), A358721, A358722.
Showing 1-3 of 3 results.