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.

Previous Showing 11-15 of 15 results.

A270962 Number of set partitions of [n] having exactly eight pairs (m,m+1) such that m+1 is in some block b and m is in block b+1.

Original entry on oeis.org

15, 857, 21129, 361154, 5138182, 66407157, 816411988, 9796844472, 116493895521, 1385342513224, 16571907424860, 200166968890873, 2447436683633895, 30343738969483443, 381914993014556712, 4883614045607479339, 63476602847240143719, 838919983940694715522
Offset: 13

Views

Author

Alois P. Heinz, Mar 26 2016

Keywords

Examples

			a(13) = 15: 1369(13)|258(12)|47(11)|(10), 136(10)(13)|259(12)|48(11)|7, 136(10)|259(13)|48(12)|7(11), 136(10)|259|48(13)|7(12)|(11), 136(13)|259(12)|48(11)|7(10), 136|259(13)|48(12)|7(11)|(10), 136(13)|25(12)|48(11)|7(10)|9, 139(13)|258(12)|47(11)|6(10), 139|258(13)|47(12)|6(11)|(10), 13(13)|258(12)|47(11)|6(10)|9, 138(13)|27(12)|46(11)|5(10)|9, 159(13)|248(12)|37(11)|6(10), 159|248(13)|37(12)|6(11)|(10), 15(13)|248(12)|37(11)|6(10)|9, 18(13)|247(12)|36(11)|5(10)|9.

Links

Crossrefs

Column k=8 of A270953.

A270963 Number of set partitions of [n] having exactly nine pairs (m,m+1) such that m+1 is in some block b and m is in block b+1.

Original entry on oeis.org

5, 522, 17506, 368606, 6131236, 89714397, 1222378331, 16017586392, 205773378304, 2622730297478, 33419633878019, 427875505471609, 5523038725443790, 72044774875932494, 951266975170654957, 12728521821662549888, 172734660881786725453, 2378751774455132263522
Offset: 14

Views

Author

Alois P. Heinz, Mar 26 2016

Keywords

Links

Crossrefs

Column k=9 of A270953.

A270964 Number of set partitions of [n] having exactly ten pairs (m,m+1) such that m+1 is in some block b and m is in block b+1.

Original entry on oeis.org

1, 281, 13297, 348523, 6807872, 113042841, 1709159987, 24469725009, 339634663517, 4638106688642, 62916588549562, 853199404241913, 11616795214297568, 159290998975659690, 2204454156023259166, 30838108887627521579, 436552647970998600862, 6258905749718943712307
Offset: 15

Views

Author

Alois P. Heinz, Mar 26 2016

Keywords

Links

Crossrefs

Column k=10 of A270953.

A270967 Number of set partitions of [n] having the maximal possible number of pairs (m,m+1) such that m+1 is in some block b and m is in block b+1.

Original entry on oeis.org

1, 1, 2, 1, 6, 3, 1, 21, 10, 4, 1, 76, 36, 15, 5, 1, 281, 133, 57, 21, 6, 1, 1052, 499, 218, 85, 28, 7, 1, 3974, 1890, 838, 339, 121, 36, 8, 1, 15113, 7207, 3233, 1343, 505, 166, 45, 9, 1, 57774, 27622, 12509, 5302, 2069, 726, 221, 55, 10, 1, 221781, 106289
Offset: 0

Views

Author

Alois P. Heinz, Mar 26 2016

Keywords

Links

Crossrefs

Cf. A083920, A270953.

Formula

a(n) = A270953(n,n-floor((1+sqrt(max(0,8*n-7)))/2)).

A270965 Number of set partitions of [2n] having exactly n pairs (m,m+1) such that m+1 is in some block b and m is in block b+1.

Original entry on oeis.org

1, 0, 0, 1, 10, 127, 1650, 23258, 361154, 6131236, 113042841, 2248848796, 47985568177, 1092290052791, 26397613960112, 674479517926073, 18153075875657428, 512977569857121559, 15176209471995304906, 468847646698743759887, 15090613008931715532300
Offset: 0

Views

Author

Alois P. Heinz, Mar 26 2016

Keywords

Examples

			a(3) = 1: 136|25|4.
a(4) = 10: 1358|247|6, 1368|257|4, 136|258|47, 136|25|48|7, 138|257|46, 13|258|47|6, 138|27|46|5, 158|247|36, 15|248|37|6, 18|247|36|5.
a(5) = 127: 1247(10)|369|58, 1247|36(10)|59|8, 124(10)|369|58|7, ..., 1(10)|269|358|47, 1|26(10)|359|48|7, 1(10)|29|358|47|6.

Links

Crossrefs

Cf. A270953.

Formula

a(n) = A270953(2n,n).
Previous Showing 11-15 of 15 results.

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