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 19 results. Next

A376370 Square array read by antidiagonals: row n lists numbers that occur exactly n times in A036038 (or A050382 or A078760 or A318762), i.e., numbers m such that the multinomial coefficient (x_1 + ... + x_k)!/(x_1! * ... * x_k!) is equal to m for exactly n integer partitions (x_1, ..., x_k).

Original entry on oeis.org

2, 3, 10, 4, 12, 6, 5, 15, 20, 420, 7, 21, 30, 630, 120, 8, 24, 56, 840, 1680, 210, 9, 28, 60, 1980, 60060, 1260, 4324320, 11, 35, 90, 3003, 83160, 2520, 21621600, 7207200, 13, 36, 105, 7140, 180180, 5040, 24504480, 151351200, 720720
Offset: 1

Views

Author

Pontus von Brömssen, Sep 22 2024

Keywords

Comments

Row n lists numbers m such that A376369(m) = n.
In case there are only finitely many solutions for a certain value of n, the rest of that row is filled with 0's.
Any integer k >= 2 appears exactly once in the array.

Examples

			Array begins:
  n\k|       1         2         3         4         5          6          7          8
  ---+---------------------------------------------------------------------------------
  1  |       2         3         4         5         7          8          9         11
  2  |      10        12        15        21        24         28         35         36
  3  |       6        20        30        56        60         90        105        252
  4  |     420       630       840      1980      3003       7140       7560       9240
  5  |     120      1680     60060     83160    180180     240240     831600     900900
  6  |     210      1260      2520      5040     27720     166320    1441440    4084080
  7  | 4324320  21621600  24504480  43243200  75675600  116396280  367567200  908107200
  8  | 7207200 151351200 302702400 411863760 823727520 1816214400 2327925600 4655851200
		

Crossrefs

Cf. A036038, A050382, A078760, A318762, A325472 (complement of first row), A325593 (complement of the union of the first 2 rows), A376369, A376376 (first column).
First five rows are A376371, A376372, A376373, A376374, A376375.

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.

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.

A376840 Take the integer partitions with at least 2 parts in order of their associated multinomial coefficients; a(n) is the sum of the n-th partition, i.e., the number of the row of A036038 (or A078760) in which the multinomial coefficient appears. In case of ties, take the sums (or row numbers) in nondecreasing order.

Original entry on oeis.org

2, 3, 4, 5, 3, 4, 6, 7, 8, 9, 5, 10, 11, 4, 12, 13, 14, 6, 15, 16, 17, 18, 19, 5, 6, 20, 7, 21, 22, 23, 4, 24, 25, 26, 27, 8, 28, 29, 5, 6, 30, 31, 32, 33, 34, 7, 35, 9, 36, 37, 38, 39, 40, 41, 7, 42, 43, 44, 10, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 11, 55
Offset: 1

Views

Author

Pontus von Brömssen, Oct 06 2024

Keywords

Comments

Equivalently, a(n) is the number of the row of A036038 (or A078760) in which A376367(n) appears, with row numbers in nondecreasing order for numbers that appear multiple times in A376367.
The multinomial coefficient of the n-th partition, with the ordering considered here, is A376367(n).

Examples

			  n | A376367(n) | partition | a(n)
  --+------------+-----------+-----
  1 |     2      |  (1,1)    |  2
  2 |     3      |  (2,1)    |  3
  3 |     4      |  (3,1)    |  4
  4 |     5      |  (4,1)    |  5
  5 |     6      |  (1,1,1)  |  3
  6 |     6      |  (2,2)    |  4
  7 |     6      |  (5,1)    |  6
		

Crossrefs

Formula

a(n) = A056239(A376379(n)).

A036038 Triangle of multinomial coefficients.

Original entry on oeis.org

1, 1, 2, 1, 3, 6, 1, 4, 6, 12, 24, 1, 5, 10, 20, 30, 60, 120, 1, 6, 15, 20, 30, 60, 90, 120, 180, 360, 720, 1, 7, 21, 35, 42, 105, 140, 210, 210, 420, 630, 840, 1260, 2520, 5040, 1, 8, 28, 56, 70, 56, 168, 280, 420, 560, 336, 840, 1120, 1680, 2520, 1680, 3360, 5040, 6720
Offset: 1

Views

Author

Keywords

Comments

The number of terms in the n-th row is the number of partitions of n, A000041(n). - Amarnath Murthy, Sep 21 2002
For each n, the partitions are ordered according to A-St: first by length and then lexicographically (arranging the parts in nondecreasing order), which is different from the usual practice of ordering all partitions lexicographically. - T. D. Noe, Nov 03 2006
For this ordering of the partitions, for n >= 1, see the remarks and the C. F. Hindenburg link given in A036036. - Wolfdieter Lang, Jun 15 2012
The relation (n+1) * A134264(n+1) = A248120(n+1) / a(n) where the arithmetic is performed for matching partitions in each row n connects the combinatorial interpretations of this array to some topological and algebraic constructs of the two other entries. Also, these seem (cf. MOPS reference, Table 2) to be the coefficients of the Jack polynomial J(x;k,alpha=0). - Tom Copeland, Nov 24 2014
The conjecture on the Jack polynomials of zero order is true as evident from equation a) on p. 80 of the Stanley reference, suggested to me by Steve Kass. The conventions for denoting the more general Jack polynomials J(n,alpha) vary. Using Stanley's convention, these Jack polynomials are the umbral extensions of the multinomial expansion of (s_1*x_1 + s_2*x_2 + ... + s_(n+1)*x_(n+1))^n in which the subscripts of the (s_k)^j in the symmetric monomial expansions are finally ignored and the exponent dropped to give s_j(alpha) = j-th row polynomial of A094638 or |A008276| in ascending powers of alpha. (The MOPS table has some inconsistency between n = 3 and n = 4.) - Tom Copeland, Nov 26 2016

Examples

			1;
1, 2;
1, 3,  6;
1, 4,  6, 12, 24;
1, 5, 10, 20, 30, 60, 120;
1, 6, 15, 20, 30, 60,  90, 120, 180, 360, 720;
		

References

  • Abramowitz and Stegun, Handbook, p. 831, column labeled "M_1".

Crossrefs

Cf. A036036-A036040. Different from A078760. Row sums give A005651.
Cf. A183610 is a table of sums of powers of terms in rows.
Cf. A134264 and A248120.
Cf. A096162 for connections to A130561.

Programs

  • Maple
    nmax:=7: with(combinat): for n from 1 to nmax do P(n):=sort(partition(n)): for r from 1 to numbpart(n) do B(r):=P(n)[r] od: for m from 1 to numbpart(n) do s:=0: j:=0: while sA036038(n, m) := n!/ (mul((t!)^q(t), t=1..n)); od: od: seq(seq(A036038(n, m), m=1..numbpart(n)), n=1..nmax); # Johannes W. Meijer, Jul 14 2016
  • Mathematica
    Flatten[Table[Apply[Multinomial, Reverse[Sort[IntegerPartitions[i],  Length[ #1]>Length[ #2]&]], {1}], {i,9}]] (* T. D. Noe, Nov 03 2006 *)
  • Sage
    def ASPartitions(n, k):
        Q = [p.to_list() for p in Partitions(n, length=k)]
        for q in Q: q.reverse()
        return sorted(Q)
    def A036038_row(n):
        return [multinomial(p) for k in (0..n) for p in ASPartitions(n, k)]
    for n in (1..10): print(A036038_row(n))
    # Peter Luschny, Dec 18 2016, corrected Apr 30 2022

Formula

The n-th row is the expansion of (x_1 + x_2 + ... + x_(n+1))^n in the basis of the monomial symmetric polynomials (m.s.p.). E.g., (x_1 + x_2 + x_3 + x_4)^3 = m[3](x_1,..,x_4) + 3*m[1,2](x_1,..,x_4) + 6*m[1,1,1](x_1,..,x_4) = (Sum_{i=1..4} x_i^3) + 3*(Sum_{i,j=1..4;i != j} x_i^2 x_j) + 6*(Sum_{i,j,k=1..4;i < j < k} x_i x_j x_k). The number of indeterminates can be increased indefinitely, extending each m.s.p., yet the expansion coefficients remain the same. In each m.s.p., unique combinations of exponents and subscripts appear only once with a coefficient of unity. Umbral reduction by replacing x_k^j with x_j in the expansions gives the partition polynomials of A248120. - Tom Copeland, Nov 25 2016
From Tom Copeland, Nov 26 2016: (Start)
As an example of the umbral connection to the Jack polynomials: J(3,alpha) = (Sum_{i=1..4} x_i^3)*s_3(alpha) + 3*(Sum_{i,j=1..4;i!=j} x_i^2 x_j)*s_2(alpha)*s_1(alpha)+ 6*(Sum_{i,j,k=1..4;i < j < k} x_i x_j x_k)*s_1(alpha)*s_1(alpha)*s_1(alpha) = (Sum_{i=1..4} x_i^3)*(1+alpha)*(1+2*alpha)+ 3*(sum_{i,j=1..4;i!=j} x_i^2 x_j)*(1+alpha) + 6*(Sum_{i,j,k=1..4;i < j < k} x_i x_j x_k).
See the Copeland link for more relations between the multinomial coefficients and the Jack symmetric functions. (End)

Extensions

More terms from David W. Wilson and Wouter Meeussen
Showing 1-10 of 19 results. Next