A022915 -id:A022915 - cp's OEIS frontend

A327803 Sum T(n,k) of multinomials M(n; lambda), where lambda ranges over all partitions of n into parts that form a set of size k; triangle T(n,k), n>=0, 0<=k<=A003056(n), read by rows.

1, 0, 1, 0, 3, 0, 7, 3, 0, 31, 16, 0, 121, 125, 0, 831, 711, 60, 0, 5041, 5915, 525, 0, 42911, 46264, 6328, 0, 364561, 438681, 67788, 0, 3742453, 4371085, 753420, 12600, 0, 39916801, 49321745, 8924685, 166320, 0, 486891175, 588219523, 113501784, 2966040

Offset: 0

Alois P. Heinz, Sep 25 2019

			Triangle T(n,k) begins:
  1;
  0,       1;
  0,       3;
  0,       7,       3;
  0,      31,      16;
  0,     121,     125;
  0,     831,     711,     60;
  0,    5041,    5915,    525;
  0,   42911,   46264,   6328;
  0,  364561,  438681,  67788;
  0, 3742453, 4371085, 753420, 12600;
  ...

Alois P. Heinz, Rows n = 0..200, flattened
Wikipedia, Multinomial coefficients
Wikipedia, Partition (number theory)

Columns k=0-2 give: A000007, A061095, A327826.
Row sums give A005651.
Cf. A000217, A003056, A022915, A131632 (when the parts are distinct), A226874.

with(combinat):
T:= (n, k)-> add(multinomial(add(i, i=l), l[], 0), l=
             select(x-> nops({x[]})=k, partition(n))):
seq(seq(T(n, k), k=0..floor((sqrt(1+8*n)-1)/2)), n=0..14);
# second Maple program:
b:= proc(n, i) option remember; expand(`if`(n=0, 1,
      `if`(i<1, 0, add(x^signum(j)*b(n-i*j, i-1)*
      combinat[multinomial](n, n-i*j, i$j), j=0..n/i))))
    end:
T:= n-> (p-> seq(coeff(p, x, i), i=0..degree(p)))(b(n$2)):
seq(T(n), n=0..14);

multinomial[n_, k_List] := n!/Times @@ (k!);
b[n_, i_] := b[n, i] = Expand[If[n == 0, 1, If[i<1, 0, Sum[x^Sign[j]*b[n - i*j, i-1]*multinomial[n, Join[{n-i*j}, Table[i, {j}]]], {j, 0, n/i}]]]];
T[n_] := CoefficientList[b[n, n], x];
T /@ Range[0, 14] // Flatten (* Jean-François Alcover, May 06 2020, after 2nd Maple program *)

T(n*(n+1)/2,n) = T(A000217(n),n) = A022915(n).

A337069 Number of strict factorizations of the superprimorial A006939(n).

Original entry on oeis.org

1, 1, 3, 34, 1591, 360144, 442349835, 3255845551937, 156795416820025934, 53452979022001011490033, 138542156296245533221812350867, 2914321438328993304235584538307144802, 528454951438415221505169213611461783474874149, 873544754831735539240447436467067438924478174290477803

Offset: 0

Gus Wiseman, Aug 15 2020

nonn

The n-th superprimorial is A006939(n) = Product_{i = 1..n} prime(i)^(n - i + 1).

Also the number of strict multiset partitions of {1,2,2,3,3,3,...,n}, a multiset with i copies of i for i = 1..n.

			The a(3) = 34 factorizations:
  2*3*4*15  2*3*60   2*180  360
  2*3*5*12  2*4*45   3*120
  2*3*6*10  2*5*36   4*90
  2*4*5*9   2*6*30   5*72
  3*4*5*6   2*9*20   6*60
            2*10*18  8*45
            2*12*15  9*40
            3*4*30   10*36
            3*5*24   12*30
            3*6*20   15*24
            3*8*15   18*20
            3*10*12
            4*5*18
            4*6*15
            4*9*10
            5*6*12
            5*8*9

A022915 counts permutations of the same multiset.
A157612 is the version for factorials instead of superprimorials.
A317829 is the non-strict version.
A337072 is the non-strict version with squarefree factors.
A337073 is the case with squarefree factors.
A000217 counts prime factors (with multiplicity) of superprimorials.
A001055 counts factorizations.
A006939 lists superprimorials or Chernoff numbers.
A045778 counts strict factorizations.
A076954 can be used instead of A006939 (cf. A307895, A325337).
A181818 lists products of superprimorials, with complement A336426.
A322583 counts factorizations into factorials.
Cf. A000142, A000178, A002110, A022559, A027423, A303279, A318286, A322583, A337070, A337071.

chern[n_]:=Product[Prime[i]^(n-i+1),{i,n}];
stfa[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[stfa[n/d],Min@@#>d&]],{d,Rest[Divisors[n]]}]];
Table[Length[stfa[chern[n]]],{n,0,3}]

\\ See A318286 for count.
a(n) = {if(n==0, 1, count(vector(n, i, i)))} \\ Andrew Howroyd, Sep 01 2020

a(n) = A045778(A006939(n)).

a(n) = A318286(A002110(n)). - Andrew Howroyd, Sep 01 2020

a(7)-a(13) from Andrew Howroyd, Sep 01 2020

A246292 Number of permutations on [n*(n+1)/2] with cycles of n distinct lengths.

Original entry on oeis.org

1, 1, 3, 120, 151200, 10897286400, 70959641905152000, 60493719168990845337600000, 9226024969987629401488081551360000000, 329646772667218349211759153151614073700352000000000, 3498788402132461399351052923160966975192989707740695756800000000000

Offset: 0

Alois P. Heinz, Aug 21 2014

nonn

Alois P. Heinz, Table of n, a(n) for n = 0..30

Cf. A000142, A000178, A000217, A022915, A218868, A242027, A317165.

a:= n-> binomial(n+1, 2)!/n!:
seq(a(n), n=0..12);

a(n) = C(n+1,2)! / n!.
a(n) = A218868(n*(n+1)/2,n) = A218868(A000217(n),n).
a(n) = A242027(n*(n+1)/2,n) = A242027(A000217(n),n).
a(n) = A022915(n) * A000178(n-1) for n>0.

A336497 Numbers that cannot be written as a product of superfactorials A000178.

Original entry on oeis.org

3, 5, 6, 7, 9, 10, 11, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76

Offset: 1

Gus Wiseman, Aug 03 2020

nonn

First differs from A336426 in having 360.

			The sequence of terms together with their prime indices begins:
     3: {2}        22: {1,5}        39: {2,6}
     5: {3}        23: {9}          40: {1,1,1,3}
     6: {1,2}      25: {3,3}        41: {13}
     7: {4}        26: {1,6}        42: {1,2,4}
     9: {2,2}      27: {2,2,2}      43: {14}
    10: {1,3}      28: {1,1,4}      44: {1,1,5}
    11: {5}        29: {10}         45: {2,2,3}
    13: {6}        30: {1,2,3}      46: {1,9}
    14: {1,4}      31: {11}         47: {15}
    15: {2,3}      33: {2,5}        49: {4,4}
    17: {7}        34: {1,7}        50: {1,3,3}
    18: {1,2,2}    35: {3,4}        51: {2,7}
    19: {8}        36: {1,1,2,2}    52: {1,1,6}
    20: {1,1,3}    37: {12}         53: {16}
    21: {2,4}      38: {1,8}        54: {1,2,2,2}

A093373 is the version for factorials, with complement A001013.
A336426 is the version for superprimorials, with complement A181818.
A336496 is the complement.
A000178 lists superfactorials.
A001055 counts factorizations.
A006939 lists superprimorials or Chernoff numbers.
A049711 is the minimum prime multiplicity in A000178(n).
A174605 is the maximum prime multiplicity in A000178(n).
A303279 counts prime factors (with multiplicity) of superprimorials.
A317829 counts factorizations of superprimorials.
A322583 counts factorizations into factorials.
A325509 counts factorizations of factorials into factorials.
Cf. A000142, A000720, A007489, A011371, A022559, A022915, A027423, A034878, A034876, A076954, A115627, A294068.

supfac[n_]:=Product[k!,{k,n}];
facsusing[s_,n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[facsusing[Select[s,Divisible[n/d,#]&],n/d],Min@@#>=d&]],{d,Select[s,Divisible[n,#]&]}]];
Select[Range[100],facsusing[Rest[Array[supfac,30]],#]=={}&]

A337072 Number of factorizations of the superprimorial A006939(n) into squarefree numbers > 1.

Original entry on oeis.org

1, 1, 2, 10, 141, 6769, 1298995, 1148840085, 5307091649182, 143026276277298216, 24801104674619158730662, 30190572492693121799801655311, 278937095127086600900558327826721594

Offset: 0

Gus Wiseman, Aug 15 2020

The n-th superprimorial is A006939(n) = Product_{i = 1..n} prime(i)^(n - i + 1), which has n! divisors.

Also the number of set multipartitions (multisets of sets) of the multiset of prime factors of the superprimorial A006939(n).

			The a(1) = 1 through a(3) = 10 factorizations:
    2  2*6    2*6*30
       2*2*3  6*6*10
              2*5*6*6
              2*2*3*30
              2*2*6*15
              2*3*6*10
              2*2*3*5*6
              2*2*2*3*15
              2*2*3*3*10
              2*2*2*3*3*5
The a(1) = 1 through a(3) = 10 set multipartitions:
     {1}  {1}{12}    {1}{12}{123}
          {1}{1}{2}  {12}{12}{13}
                     {1}{1}{12}{23}
                     {1}{1}{2}{123}
                     {1}{2}{12}{13}
                     {1}{3}{12}{12}
                     {1}{1}{1}{2}{23}
                     {1}{1}{2}{2}{13}
                     {1}{1}{2}{3}{12}
                     {1}{1}{1}{2}{2}{3}

A000142 counts divisors of superprimorials.
A022915 counts permutations of the same multiset.
A103774 is the version for factorials instead of superprimorials.
A337073 is the strict case (strict factorizations into squarefree numbers).
A001055 counts factorizations.
A006939 lists superprimorials or Chernoff numbers.
A045778 counts strict factorizations.
A050320 counts factorizations into squarefree numbers.
A050326 counts strict factorizations into squarefree numbers.
A076954 can be used instead of A006939 (cf. A307895, A325337).
A089259 counts set multipartitions of integer partitions.
A116540 counts normal set multipartitions.
A317829 counts factorizations of superprimorials.
A337069 counts strict factorizations of superprimorials.
Cf. A000178, A002110, A027423, A124010, A181818, A303279, A318360, A336417, A337070.

chern[n_]:=Product[Prime[i]^(n-i+1),{i,n}];
facsqf[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[facsqf[n/d],Min@@#>=d&]],{d,Select[Rest[Divisors[n]],SquareFreeQ]}]];
Table[Length[facsqf[chern[n]]],{n,0,3}]

\\ See A318360 for count.
a(n) = {if(n==0, 1, count(vector(n,i,i)))} \\ Andrew Howroyd, Aug 31 2020

a(n) = A050320(A006939(n)).

a(n) = A318360(A002110(n)). - Andrew Howroyd, Aug 31 2020

a(7)-a(12) from Andrew Howroyd, Aug 31 2020

A290517 Maximum value of the multinomial coefficients M(n;lambda), where lambda ranges over all partitions of n into distinct parts.

Original entry on oeis.org

1, 1, 1, 3, 4, 10, 60, 105, 280, 1260, 12600, 27720, 83160, 360360, 2522520, 37837800, 100900800, 343062720, 1543782240, 9777287520, 97772875200, 2053230379200, 6453009763200, 24736537425600, 118735379642880, 742096122768000, 6431499730656000

Offset: 0

Alois P. Heinz, Aug 04 2017

nonn

			a(10) = 12600 = 10! / (4! * 3! * 2! * 1!) is the value for partition [4,3,2,1]. All other partitions of 10 into distinct parts give smaller values: [5,3,2]-> 2520, [5,4,1]-> 1260, [6,3,1]-> 840, [6,4]-> 210, [7,2,1]-> 360, [7,3]-> 120, [8,2]-> 45, [9,1]-> 10, [10]-> 1.

Alois P. Heinz, Table of n, a(n) for n = 0..697
Wikipedia, Multinomial coefficients

Cf. A000009, A000142, A000178, A004736, A022915, A290518, A309992.

b:= proc(n, i) option remember; `if`(n>i*(i+1)/2, infinity,
     `if`(n=0, 1, min(b(n, i-1), b(n-i, min(n-i, i-1))*i!)))
    end:
a:= n-> n!/b(n$2):
seq(a(n), n=0..30);
# second Maple program:
a:= proc(n) option remember; `if`(n=0, 1, a(n-1)*n/
      (t-> t*(t+3)/2-n+2)(floor(sqrt(8*n-7)/2-1/2)))
    end:
seq(a(n), n=0..30);  # Alois P. Heinz, Aug 05 2017

b[n_, i_]:=b[n, i]=If[n>i*(i + 1)/2, Infinity, If[n==0, 1, Min[b[n, i - 1], b[n - i, Min[n - i, i - 1]]*i!]]]; Table[n!/b[n, n], {n, 0, 30}] (* Indranil Ghosh, Aug 05 2017, after Maple *)

a(n) = A000142(n) / A290518(n).
a(0) = 1, a(n) = n * a(n-1) / A004736(n) for n>0.
a(n) = A309992(n,A000009(n)). - Alois P. Heinz, Aug 26 2019

A337073 Number of strict factorizations of the superprimorial A006939(n) into squarefree numbers > 1.

Original entry on oeis.org

1, 1, 1, 2, 14, 422, 59433, 43181280, 178025660042, 4550598470020490, 782250333882971717562, 974196106965358319940100513, 9412280190038329162111356578977100, 751537739224674099813783040471383322758327

Offset: 0

Gus Wiseman, Aug 15 2020

The n-th superprimorial is A006939(n) = Product_{i = 1..n} prime(i)^(n - i + 1). It has n! divisors.

Also the number of strict set multipartitions (sets of sets) of the multiset of prime factors of the superprimorial A006939(n).

			The a(1) = 1 through a(3) = 10 factorizations:
    2  2*6  2*6*30    2*6*30*210
            2*3*6*10  6*10*30*42
                      2*3*6*30*70
                      2*5*6*30*42
                      2*3*10*30*42
                      2*3*6*10*210
                      2*6*10*15*42
                      2*6*10*21*30
                      2*6*14*15*30
                      3*6*10*14*30
                      2*3*5*6*10*42
                      2*3*5*6*14*30
                      2*3*6*7*10*30
                      2*3*6*10*14*15
The a(1) = 1 through a(3) = 14 set multipartitions:
    {1}  {1}{12}  {1}{12}{123}    {1}{12}{123}{1234}
                  {1}{2}{12}{13}  {12}{13}{123}{124}
                                  {1}{12}{13}{23}{124}
                                  {1}{12}{13}{24}{123}
                                  {1}{12}{14}{23}{123}
                                  {1}{2}{12}{123}{134}
                                  {1}{2}{12}{13}{1234}
                                  {1}{2}{13}{123}{124}
                                  {1}{3}{12}{123}{124}
                                  {2}{12}{13}{14}{123}
                                  {1}{2}{12}{13}{14}{23}
                                  {1}{2}{12}{4}{13}{123}
                                  {1}{2}{3}{12}{13}{124}
                                  {1}{2}{3}{12}{14}{123}

A000142 counts divisors of superprimorials.
A022915 counts permutations of the same multiset.
A103775 is the version for factorials instead of superprimorials.
A337072 is the non-strict version.
A001055 counts factorizations.
A006939 lists superprimorials or Chernoff numbers.
A045778 counts strict factorizations.
A050320 counts factorizations into squarefree numbers.
A050326 counts strict factorizations into squarefree numbers.
A050342 counts strict set multipartitions of integer partitions.
A076954 can be used instead of A006939 (cf. A307895, A325337).
A283877 counts non-isomorphic strict set multipartitions.
A317829 counts factorizations of superprimorials.
A337069 counts strict factorizations of superprimorials.
Cf. A000178, A002110, A022559, A103774, A124010, A181818, A318361, A336417, A337070.

chern[n_]:=Product[Prime[i]^(n-i+1),{i,n}];
ystfac[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[ystfac[n/d],Min@@#>d&]],{d,Select[Rest[Divisors[n]],SquareFreeQ]}]];
Table[Length[ystfac[chern[n]]],{n,0,4}]

\\ See A318361 for count.
a(n) = {if(n==0, 1, count(vector(n, i, i)))} \\ Andrew Howroyd, Sep 01 2020

a(n) = A050326(A006939(n)).

a(n) = A318361(A002110(n)). - Andrew Howroyd, Sep 01 2020

a(7)-a(13) from Andrew Howroyd, Sep 01 2020

A022919 Multinomial coefficients(TOP, BOTTOM), where TOP = n^2, BOTTOM = ( 1 3 5 ... 2n-1 ).

Original entry on oeis.org

1, 1, 4, 504, 5765760, 11779303536000, 7077067947620326656000, 1858415281524390197256677213184000, 296452547038365950028519606090501848174100480000, 38078735219928394229608103398446248260205826730163060269056000000

Offset: 0

Clark Kimberling

nonn

Alois P. Heinz, Table of n, a(n) for n = 0..25

Cf. A022915.

with(combinat):
a:= n-> multinomial(n^2, (2*i-1)$i=1..n, 0):
seq(a(n), n=0..10);  # Alois P. Heinz, Aug 05 2014

multinomial[n_, k_List] := n!/Times @@ (k!);
a[n_] := multinomial[n^2, Range[1, 2n-1, 2]];
Table[a[n], {n, 0, 10}] (* Jean-François Alcover, Jan 02 2025 *)

More terms from Vladimir Joseph Stephan Orlovsky, Dec 26 2010

A175356 Those positive integers n where, when written in binary, there are exactly k number of runs (of either 0's or 1's) each of exactly k length, for all k where 1<=k<=m, for some positive integer m.

Original entry on oeis.org

1, 19, 25, 27, 8984, 8988, 9016, 9100, 9112, 9116, 9784, 10008, 10012, 10040, 12568, 12572, 12600, 12680, 12686, 12728, 12740, 12742, 12744, 12750, 12760, 12764, 12856, 13192, 13198, 13240, 13880, 14104, 14108, 14136, 14476, 14488, 14492, 14532, 14534, 14536

Offset: 1

Leroy Quet, Apr 22 2010

A "run" of 0's is not immediately bounded by any 0's, and a "run" of 1's is not immediately bounded by any 1's.
There are exactly (m*(m+1)/2)! / Product_{k=1 to m} k! numbers in the sequence each of m^3/3 + m^2/2 + m/6 binary digits, for all m >= 1, and none of any other number of binary digits.
A005811(a(n)) is triangular, i.e., in A000217. - Michael S. Branicky, Jan 19 2021

			9016 in binary is 10001100111000. There is exactly one run of one binary digit, two runs of two binary digits, and three runs of three binary digits. (Note that it doesn't matter if the runs are of 0's or of 1's.) So, 9016 is in the sequence.

Rémy Sigrist, Table of n, a(n) for n = 1..12664
Rémy Sigrist, PARI program for A175356

Cf. A000330, A022915, A175061, A175357.

Cf. A005811, A000217.

PARI
```
\\ See Links section.
```

from itertools import groupby
def ok(n):
  runlens = [len(list(g)) for k, g in groupby(bin(n)[2:])]
  return all(runlens.count(k) == k for k in range(1, max(runlens)+1))
def aupto(limit): return [m for m in range(1, limit+1) if ok(m)]
print(aupto(14536)) # Michael S. Branicky, Jan 19 2021

More terms from Rémy Sigrist, Feb 06 2019

A175357 Irregular array: Row n contains the run-lengths (of runs of both 0's and 1's) of the binary representation of A175356(n).

Original entry on oeis.org

1, 1, 2, 2, 2, 2, 1, 2, 1, 2, 1, 3, 2, 3, 2, 3, 1, 3, 2, 3, 3, 2, 1, 3, 2, 2, 3, 3, 1, 3, 3, 3, 2, 2, 1, 3, 3, 2, 2, 3, 1, 3, 3, 2, 3, 2, 1, 2, 2, 3, 3, 3, 1, 2, 3, 3, 2, 3, 1, 2, 3, 3, 3, 2, 1, 2, 3, 2, 3, 3, 2, 3, 1, 3, 2, 3, 2, 3, 1, 3, 3, 2, 2, 3, 1, 2, 3

Offset: 1

Leroy Quet, Apr 22 2010

This array orders the distinct permutations each of one 1, two 2's, three 3's..., m number of m's, for a positive integer m.

The number of terms per row is nondecreasing. There are exactly (m(m+1)/2)!/product{k=1 to m}k! rows in the sequence each of m(m+1)/2 terms, for all m >= 1, and none of any other number of terms.

			8984, the fifth term of A175356, is 10001100011000 in binary. There is a run of one 1, followed by a run of three 0's, followed by a run of two 1's, followed by a run of three 0's, followed by a run of two 1's, followed finally by a run of three 0's. So, row 5 is 1,3,2,3,2,3.

Rémy Sigrist, PARI program for A175357

Cf. A175356, A022915.

PARI
```
See Links section.
```

Example changed and tabf keyword added by Leroy Quet, Apr 27 2010

More terms from Rémy Sigrist, Feb 06 2019

cp's OEIS Frontend

A327803 Sum T(n,k) of multinomials M(n; lambda), where lambda ranges over all partitions of n into parts that form a set of size k; triangle T(n,k), n>=0, 0<=k<=A003056(n), read by rows.

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A337069 Number of strict factorizations of the superprimorial A006939(n).

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A246292 Number of permutations on [n*(n+1)/2] with cycles of n distinct lengths.

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A336497 Numbers that cannot be written as a product of superfactorials A000178.

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A337072 Number of factorizations of the superprimorial A006939(n) into squarefree numbers > 1.

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A290517 Maximum value of the multinomial coefficients M(n;lambda), where lambda ranges over all partitions of n into distinct parts.

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A337073 Number of strict factorizations of the superprimorial A006939(n) into squarefree numbers > 1.

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Mathematica

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A022919 Multinomial coefficients(TOP, BOTTOM), where TOP = n^2, BOTTOM = ( 1 3 5 ... 2n-1 ).

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