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 1-10 of 11 results. Next

A376667 Square array read by antidiagonals: row n lists numbers whose maximal frequency in a fixed row of A036038 (or A078760) is equal to n, i.e., numbers m such that A376663(m) = n.

Original entry on oeis.org

1, 2, 56, 3, 210, 166320, 4, 504, 360360, 4084080, 5, 1260, 720720, 17907120, 1396755360, 6, 1365, 2162160, 73513440, 4190266080, 698377680, 7, 1680, 5045040, 75675600, 4655851200, 13967553600, 146659312800, 8, 1716, 5765760, 220540320, 4942365120, 27935107200, 293318625600, 1075501627200
Offset: 1

Views

Author

Pontus von Brömssen, Oct 02 2024

Keywords

Comments

In case there are only finitely many solutions for a certain value of n, the rest of that row is filled with 0's.
Each positive integer appears exactly once in the array, so as a linear sequence it is a permutation of the positive integers (unless there are any 0's).

Examples

			Array begins:
  n\k|             1             2              3              4              5              6
  ---+----------------------------------------------------------------------------------------
  1  |             1             2              3              4              5              6
  2  |            56           210            504           1260           1365           1680
  3  |        166320        360360         720720        2162160        5045040        5765760
  4  |       4084080      17907120       73513440       75675600      220540320      411863760
  5  |    1396755360    4190266080     4655851200     4942365120     9884730240    24443218800
  6  |     698377680   13967553600    27935107200   267711444000   537750813600   586637251200
  7  |  146659312800  293318625600  1606268664000  3226504881600  6184134356400  7228208988000
  8  | 1075501627200 6453009763200 12368268712800 24736537425600 29683844910720 74209612276800
		

Crossrefs

Cf. A036038, A078760, A325306 (complement of first row), A376370, A376663, A376673 (first column).
First five rows are A376668, A376669, A376670, A376671, A376672.

A376673 Least number whose maximum frequency in a fixed row of A036038 (or A078760) is equal to n, i.e., least number m such that A376663(m) = n, or 0 if no such number exists.

Original entry on oeis.org

1, 56, 166320, 4084080, 1396755360, 698377680, 146659312800, 1075501627200, 37104806138400, 3710480613840000, 296838449107200, 86825246363856000, 96472495959840000, 36466603472819520000, 35251050023725536000, 272194921062320256000, 408292381593480384000
Offset: 1

Views

Author

Pontus von Brömssen, Oct 02 2024

Keywords

Comments

After a(36), the sequence continues (where "?" represents terms that are either 0 or greater than 10^29): ?, 3059734941813910128088320000, ?, ?, 64254433778092112689854720000. After a(41), all terms are either 0 or greater than 10^29.
The terms a(1), a(3), ..., a(15), a(24), a(26), ..., a(36), a(38), a(41) are all in A025487, but a(16), ..., a(23), a(25) are all divisible by 17^2 but not by 13^2.

Examples

			First few terms and their representations as multinomial coefficients (corresponding to partitions with sum A376664(n)):
  a(1) =          1 = 0!;
  a(2) =         56 = 8!/(1!*1!*6!) = 8!/(3!*5!);
  a(3) =     166320 = 12!/(1!*1!*1!*4!*5!) = 12!/(1!*1!*2!*2!*6!) = 12!/(2!*2!*3!*5!);
  a(4) =    4084080 = 17!/(1!*1!*1!*4!*10!) = 17!/(1!*2!*5!*9!) = 17!/(2!*2!*3!*10!) = 17!/(4!*6!*7!);
  a(5) = 1396755360 = 19!/(1!*1!*1!*1!*1!*4!*10!) = 19!/(1!*1!*1!*2!*5!*9!) = 19!/(1!*1!*2!*2!*3!*10!) = 19!/(1!*1!*4!*6!*7!) = 19!/(3!*4!*5!*7!).
		

Crossrefs

First column of A376667.

A376664 Least number k such that there are A376663(n) partitions x_1 + ... + x_j = k such that the multinomial coefficient k!/(x_1! * ... * x_j!) is equal to n, i.e., the first row k of A036038 in which n appears A376663(n) times (or 0 if n = 0).

Original entry on oeis.org

0, 2, 3, 4, 5, 3, 7, 8, 9, 5, 11, 4, 13, 14, 6, 16, 17, 18, 19, 5, 7, 22, 23, 4, 25, 26, 27, 8, 29, 5, 31, 32, 33, 34, 7, 9, 37, 38, 39, 40, 41, 7, 43, 44, 10, 46, 47, 48, 49, 50, 51, 52, 53, 54, 11, 8, 57, 58, 59, 5, 61, 62, 63, 64, 65, 12, 67, 68, 69, 8, 71
Offset: 1

Views

Author

Pontus von Brömssen, Oct 02 2024

Keywords

Comments

Differs from A376368 at n = 1260, 2520, 5040, 60060, 83160, ... . For example, 1260 appears first in row A376368(1260) = 7 of A036038, but only once. It also appears once in row 9, but in row a(1260) = 10 it appears A376663(1260) = 2 times.
a(n) <= n, with equality if and only if n is not in A325472.

Crossrefs

A376666 Indices of records in A376663.

Original entry on oeis.org

1, 56, 166320, 4084080, 698377680, 146659312800, 1075501627200, 37104806138400, 296838449107200, 86825246363856000, 96472495959840000, 35251050023725536000, 272194921062320256000, 408292381593480384000, 4082923815934803840000, 15106818118958774208000
Offset: 1

Views

Author

Pontus von Brömssen, Oct 02 2024

Keywords

Crossrefs

Formula

a(n) = A376673(A376665(n)).

A376665 Records in A376663.

Original entry on oeis.org

1, 2, 3, 4, 6, 7, 8, 9, 11, 12, 13, 15, 16, 17, 18, 20, 21, 23, 25, 28, 30, 31, 33, 38, 41
Offset: 1

Views

Author

Pontus von Brömssen, Oct 02 2024

Keywords

Crossrefs

Formula

a(n) = A376663(A376666(n)).

A376668 Positive integers that do not appear more than once in the same row of A036038 (or A078760), i.e., numbers m such that A376663(m) = 1.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75
Offset: 1

Views

Author

Pontus von Brömssen, Oct 02 2024

Keywords

Comments

Is this the same as A357759? - R. J. Mathar, Oct 09 2024. [Answer: No, they are different. - Andrew Howroyd, Oct 09 2024]

Examples

			56 is not a term, because it can be represented as a multinomial coefficient for 2 different partitions of 8: 56 = 8!/(1!*1!*6!) = 8!/(3!*5!).
		

Crossrefs

First row of A376667.
Complement of A325306 (with respect to the positive integers).

A376669 Positive integers whose maximum frequency in a fixed row of A036038 (or A078760) is equal to 2, i.e., numbers m such that A376663(m) = 2.

Original entry on oeis.org

56, 210, 504, 1260, 1365, 1680, 1716, 2520, 5040, 7560, 9240, 13860, 15120, 17550, 21840, 24024, 25200, 25740, 27720, 30030, 42504, 43680, 55440, 60060, 69300, 72072, 75600, 77520, 83160, 110880, 120120, 151200, 154440, 168168, 180180, 185640, 203490, 240240
Offset: 1

Views

Author

Pontus von Brömssen, Oct 02 2024

Keywords

Examples

			56 is a term, because it can be represented as a multinomial coefficient for 2 different partitions of 8 (and never for more than 2 different partitions of the same integer): 56 = 8!/(1!*1!*6!) = 8!/(3!*5!).
		

Crossrefs

Second row of A376667.
Subsequence of A325306.

A376670 Positive integers whose maximum frequency in a fixed row of A036038 (or A078760) is equal to 3, i.e., numbers m such that A376663(m) = 3.

Original entry on oeis.org

166320, 360360, 720720, 2162160, 5045040, 5765760, 6683040, 7207200, 12252240, 14414400, 15135120, 24504480, 30270240, 35814240, 36756720, 37837800, 40360320, 40840800, 46558512, 49008960, 51482970, 61261200, 86486400, 98017920, 102965940, 110270160, 116396280
Offset: 1

Views

Author

Pontus von Brömssen, Oct 02 2024

Keywords

Examples

			166320 is a term, because it can be represented as a multinomial coefficient for 3 different partitions of 12 (and never for more than 3 different partitions of the same integer): 166320 = 12!/(1!*1!*1!*4!*5!) = 12!/(1!*1!*2!*2!*6!) = 12!/(2!*2!*3!*5!).
		

Crossrefs

Third row of A376667.

A376671 Positive integers whose maximum frequency in a fixed row of A036038 (or A078760) is equal to 4, i.e., numbers m such that A376663(m) = 4.

Original entry on oeis.org

4084080, 17907120, 73513440, 75675600, 220540320, 411863760, 1102701600, 1210809600, 2162049120, 2205403200, 2327925600, 2471182560, 3087564480, 5145940800, 6983776800, 8380532160, 9777287520, 10291881600, 10296594000, 19554575040, 20583763200, 20593188000
Offset: 1

Views

Author

Pontus von Brömssen, Oct 02 2024

Keywords

Examples

			4084080 is a term, because it can be represented as a multinomial coefficient for 4 different partitions of 17 (and never for more than 4 different partitions of the same integer): 4084080 = 17!/(1!*1!*1!*4!*10!) = 17!/(1!*2!*5!*9!) = 17!/(2!*2!*3!*10!) = 17!/(4!*6!*7!).
		

Crossrefs

Fourth row of A376667.

A376672 Positive integers whose maximum frequency in a fixed row of A036038 (or A078760) is equal to 5, i.e., numbers m such that A376663(m) = 5.

Original entry on oeis.org

1396755360, 4190266080, 4655851200, 4942365120, 9884730240, 24443218800, 48886437600, 61779564000, 83805321600, 97772875200, 107550162720, 123559128000, 247118256000, 412275623760, 419026608000, 535422888000, 803134332000, 879955876800, 899510451840, 1173274502400
Offset: 1

Views

Author

Pontus von Brömssen, Oct 02 2024

Keywords

Examples

			1396755360 is a term, because it can be represented as a multinomial coefficient for 5 different partitions of 19 (and never for more than 5 different partitions of the same integer): 1396755360 = 19!/(1!*1!*1!*1!*1!*4!*10!) = 19!/(1!*1!*1!*2!*5!*9!) = 19!/(1!*1!*2!*2!*3!*10!) = 19!/(1!*1!*4!*6!*7!) = 19!/(3!*4!*5!*7!).
		

Crossrefs

Fifth row of A376667.
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