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 1-6 of 6 results.

A183264 Number of singly defective permutations of 1..n with exactly 1 maximum.

Original entry on oeis.org

0, 2, 15, 64, 220, 672, 1904, 5120, 13248, 33280, 81664, 196608, 465920, 1089536, 2519040, 5767168, 13090816, 29491200, 65994752, 146800640, 324796416, 715128832, 1567621120, 3422552064, 7444889600, 16139681792, 34879832064, 75161927680, 161531035648, 346281738240
Offset: 1

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Author

R. H. Hardin, Jan 03 2011

Keywords

Comments

A singly defective permutation omits one value and repeats another value.
a(1) is zero because there are no defective permutations of a single element.

Examples

			Some solutions for n=3 with 1 maximum:
(3,3,2) (1,3,3) (1,1,2) (2,1,1) (3,3,1) (1,3,1) (1,2,2) (2,2,1) (2,2,3).
		

Crossrefs

Column 1 of A183270.
Cf. A053220.

Formula

Conjecture: a(n) = n * (3*n-4) * 2^(n-3) for n > 1. - Andrew Howroyd, May 12 2020

Extensions

Terms a(16) and beyond from Andrew Howroyd, May 12 2020

A183265 Number of singly defective permutations of 1..n+2 with exactly 2 maxima.

Original entry on oeis.org

3, 80, 860, 6576, 42112, 242688, 1306944, 6721280, 33448448, 162435072, 774052864, 3633229824, 16842670080, 77264322560, 351273107456, 1584582819840, 7098965819392, 31609517506560, 139978221551616, 616818283642880, 2705880365662208, 11821908555202560, 51457052429516800
Offset: 1

Views

Author

R. H. Hardin, Jan 03 2011

Keywords

Comments

A singly defective permutation omits one value and repeats another value.

Examples

			Some solutions for n=3 with 2 maxima:
(1,4,2,3,2) (3,5,1,4,5) (4,1,2,5,2) (3,2,2,4,1) (2,1,4,5,2) (4,4,3,1,2).
		

Crossrefs

Column 2 of A183270.

Extensions

Terms a(14) and beyond from Andrew Howroyd, May 12 2020

A183266 Number of singly defective permutations of 1..n+4 with exactly 3 maxima.

Original entry on oeis.org

120, 3552, 57064, 681984, 6849792, 61486080, 511006848, 4019699712, 30364991488, 222472642560, 1592011745280, 11183547482112, 77409364082688, 529414815744000, 3585105638490112, 24077527815290880, 160571745918517248, 1064387288330403840, 7018456956044574720
Offset: 1

Views

Author

R. H. Hardin, Jan 03 2011

Keywords

Comments

A singly defective permutation omits one value and repeats another value.

Examples

			Some solutions for n=3 with 3 maxima:
(2,5,3,4,3,1,7) (2,1,7,4,3,6,2) (4,2,6,5,7,4,3) (4,3,3,7,2,5,1).
		

Crossrefs

Column 3 of A183270.

Extensions

Terms a(12) and beyond from Andrew Howroyd, May 12 2020

A183267 Number of singly defective permutations of 1..n+6 with exactly 4 maxima.

Original entry on oeis.org

4760, 199168, 4643712, 80506880, 1163431808, 14874150912, 174293203968, 1915121868800, 20041282099200, 201949448765440, 1975285587312640, 18866258297487360, 176760773333450752, 1630252849810636800, 14841729785246515200, 133664316735891701760, 1192882240528106127360
Offset: 1

Views

Author

R. H. Hardin, Jan 03 2011

Keywords

Comments

A singly defective permutation omits one value and repeats another value.

Examples

			Some solutions for n=2 with 4 maxima:
(7,5,3,6,1,5,2,8) (7,1,8,4,3,4,2,6) (6,3,7,2,8,3,5,4) (6,1,5,2,4,3,3,7).
		

Crossrefs

Column 4 of A183270.

Extensions

Terms a(10) and beyond from Andrew Howroyd, May 12 2020

A183268 Number of singly defective permutations of 1..n+8 with exactly 5 maxima.

Original entry on oeis.org

249984, 14548480, 469942528, 11190054912, 219921448448, 3786548183040, 59211819110400, 861044410941440, 11836043861688320, 155624676666900480, 1974466952368095232, 24334201908725022720, 292836028257957445632, 3454921061964353372160, 40092721917664469975040
Offset: 1

Views

Author

R. H. Hardin, Jan 03 2011

Keywords

Comments

A singly defective permutation omits one value and repeats another value.

Examples

			Some solutions for n=2 with 5 maxima:
(6,1,2,9,7,9,4,10,5,8) (6,1,5,3,10,9,4,8,2,4) (6,1,3,2,10,4,9,3,5,7).
		

Crossrefs

Column 5 of A183270.

Extensions

Terms a(8) and beyond from Andrew Howroyd, May 12 2020

A183269 Number of singly defective permutations of 1..n+10 with exactly 6 maxima.

Original entry on oeis.org

17512704, 1367568384, 58754129408, 1843339782144, 47298056693760, 1054131373473792, 21169370030997504, 392511831512186880, 6834948232630632448, 113176578627741941760, 1798774633880898895872, 27638898445971890896896, 412895207257905223434240, 6024032120226517270659072
Offset: 1

Views

Author

R. H. Hardin, Jan 03 2011

Keywords

Comments

A singly defective permutation omits one value and repeats another value.

Crossrefs

Column 6 of A183270.

Extensions

Terms a(6) and beyond from Andrew Howroyd, May 12 2020
Showing 1-6 of 6 results.