A047993 -id:A047993 - cp's OEIS frontend

A383094 Number of integer partitions of n having exactly one permutation with all equal run-lengths.

1, 1, 2, 2, 4, 4, 5, 6, 9, 7, 11, 10, 13, 12, 17, 14, 21, 16, 21, 18, 27, 22, 29, 22, 34, 25, 35, 28, 41, 28, 43, 30, 48, 38, 47, 38, 55, 36, 53, 46, 64, 40, 67, 42, 69, 54, 65, 46, 84, 51, 75, 62, 83, 52, 86, 62, 94, 70, 83, 58, 111, 60, 89, 80, 106, 74, 115, 66, 111

Offset: 0

Gus Wiseman, Apr 20 2025

nonn

			The partition (222211) has exactly one permutation with all equal run-lengths: (221122), so is counted under a(10).
The a(1) = 1 through a(8) = 9 partitions:
  (1)  (2)   (3)    (4)     (5)      (6)       (7)        (8)
       (11)  (111)  (22)    (221)    (33)      (322)      (44)
                    (211)   (311)    (222)     (331)      (332)
                    (1111)  (11111)  (411)     (511)      (422)
                                     (111111)  (22111)    (611)
                                               (1111111)  (2222)
                                                          (22211)
                                                          (221111)
                                                          (11111111)

The complement is ranked by A382879 \/ A383089.
For no choices we have A382915, ranks A382879.
For at least one choice we have A383013, for run-sums A383098, ranks A383110.
For more than one choice we have A383090, ranks A383089.
For at most one choice we have A383092, ranks A383091.
For run-sums instead of lengths we have A383095, ranks A383099.
Partitions of this type are ranked by A383112 = positions of 1 in A382857.
Cf. A047966, A072774, A098859, A100471, A100881, A100882, A100883, A304442.
A000041 counts integer partitions, strict A000009.
A008284 counts partitions by length, strict A008289.
A239455 counts Look-and-Say partitions, ranks A351294, conjugate A381432.
A329738 counts compositions with equal run-lengths, ranks A353744.
A329739 counts compositions with distinct run-lengths, ranks A351596, complement A351291.
A351293 counts non-Look-and-Say partitions, ranks A351295, conjugate A381433.
Cf. A047993, A362608, A381871, A382076, A382771, A383096, A383097, A383111.

Table[Length[Select[IntegerPartitions[n], Length[Select[Permutations[#], SameQ@@Length/@Split[#]&]]==1&]],{n,0,20}]

More terms from Bert Dobbelaere, Apr 26 2025

A326846 Length times maximum of the integer partition with Heinz number n.

Original entry on oeis.org

0, 1, 2, 2, 3, 4, 4, 3, 4, 6, 5, 6, 6, 8, 6, 4, 7, 6, 8, 9, 8, 10, 9, 8, 6, 12, 6, 12, 10, 9, 11, 5, 10, 14, 8, 8, 12, 16, 12, 12, 13, 12, 14, 15, 9, 18, 15, 10, 8, 9, 14, 18, 16, 8, 10, 16, 16, 20, 17, 12, 18, 22, 12, 6, 12, 15, 19, 21, 18, 12, 20, 10, 21, 24, 9, 24, 10, 18, 22, 15, 8, 26, 23, 16, 14, 28, 20, 20, 24

Offset: 1

Gus Wiseman, Jul 26 2019

nonn

The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k), so a(n) is the size of the minimal rectangle containing the Young digram of the integer partition with Heinz number n.

Cf. A047993, A056239, A061395, A106529, A112798.
Cf. A316413, A326836, A326837, A326844, A326845, A326848, A326849.
Cf. also A331297.

Table[PrimeOmega[n]*PrimePi[FactorInteger[n][[-1,1]]],{n,100}]

A326846(n) = if(1==n, 0, bigomega(n)*primepi(vecmax(factor(n)[, 1]))); \\ Antti Karttunen, Jan 18 2020

a(n) = A001222(n) * A061395(n).

More terms from Antti Karttunen, Jan 18 2020

A383508 Number of integer partitions of n that are both Look-and-Say and section-sum partitions.

Original entry on oeis.org

1, 1, 2, 2, 3, 3, 6, 7, 9, 12, 14, 19, 22, 27, 30, 35, 42, 50, 58, 68, 82, 92, 112, 126, 149, 174, 199, 225, 263, 299, 337, 388, 435, 488, 545, 635, 681, 775, 841, 948, 1051, 1181, 1271, 1446, 1553, 1765, 1896, 2141, 2285, 2608, 2799

Offset: 0

Gus Wiseman, May 17 2025

nonn

An integer partition is Look-and-Say iff it is possible to choose a disjoint family of strict partitions, one of each of its multiplicities. These are ranked by A351294.

An integer partition is section-sum iff its conjugate is Look-and-Say, meaning it is possible to choose a disjoint family of strict partitions, one of each of its positive 0-appended differences. These are ranked by A381432.

			The a(1) = 1 through a(8) = 9 partitions:
  (1)  (2)   (3)    (4)     (5)      (6)       (7)        (8)
       (11)  (111)  (22)    (311)    (33)      (322)      (44)
                    (1111)  (11111)  (222)     (331)      (332)
                                     (411)     (511)      (611)
                                     (3111)    (4111)     (2222)
                                     (111111)  (31111)    (5111)
                                               (1111111)  (41111)
                                                          (311111)
                                                          (11111111)

Ranking sequences are shown in parentheses below.
The non Wilf case is A383511 (A383518).
These partitions are ranked by (A383515).
A000041 counts integer partitions, strict A000009.
A047993 counts partitions with max part = length (A106529).
A098859 counts Wilf partitions (A130091), conjugate (A383512).
A122111 represents conjugation in terms of Heinz numbers.
A239455 counts Look-and-Say partitions (A351294), complement A351293 (A351295).
A239455 counts section-sum partitions (A381432), complement A351293 (A381433).
A336866 counts non Wilf partitions (A130092), conjugate (A383513).
A351592 counts non Wilf Look-and-Say partitions (A384006).
A383509 counts partitions that are Look-and-Say but not section-sum (A383516).
A383509 counts partitions that are not Look-and-Say but are section-sum (A384007).
A383510 counts partitions that are neither Look-and-Say nor section-sum (A383517).
Cf. A033461, A047966, A048767, A320348, A325324, A325325, A381431, A383519, A383530, A383709.

disjointFamilies[y_]:=Select[Tuples[IntegerPartitions /@ Length/@Split[y]],UnsameQ@@Join@@#&];
conj[y_]:=If[Length[y]==0,y, Table[Length[Select[y,#>=k&]],{k,1,Max[y]}]];
Table[Length[Select[IntegerPartitions[n], disjointFamilies[#]!={}&&disjointFamilies[conj[#]]!={}&]], {n,0,30}]

A326839 Numerator of A056239(n)/A061395(n) where A056239 is sum of prime indices and A061395 is maximum prime index.

Original entry on oeis.org

0, 1, 1, 2, 1, 3, 1, 3, 2, 4, 1, 2, 1, 5, 5, 4, 1, 5, 1, 5, 3, 6, 1, 5, 2, 7, 3, 3, 1, 2, 1, 5, 7, 8, 7, 3, 1, 9, 4, 2, 1, 7, 1, 7, 7, 10, 1, 3, 2, 7, 9, 4, 1, 7, 8, 7, 5, 11, 1, 7, 1, 12, 2, 6, 3, 8, 1, 9, 11, 2, 1, 7, 1, 13, 8, 5, 9, 3, 1, 7, 4, 14, 1, 2, 10

Offset: 1

Gus Wiseman, Jul 26 2019

This is a dual form of the average of an integer partition specified by its Heinz number: A326567/A326568.

			The sequence of fractions begins: 0, 1, 1, 2, 1, 3/2, 1, 3, 2, 4/3, 1, 2, 1, 5/4, 5/3, 4, 1, 5/2, 1, 5/3.

Denominators are A326840.
Positions of 1's are A000040.
Cf. A001222, A047993, A056239, A061395, A112798, A316413.
Cf. A326567/A326568, A326836, A326845, A326848, A326850.

primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
Numerator[Table[Total[primeMS[n]]/Max@@primeMS[n],{n,100}]]

A326840 Denominator of A056239(n)/A061395(n).

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 1, 1, 1, 3, 1, 1, 1, 4, 3, 1, 1, 2, 1, 3, 2, 5, 1, 2, 1, 6, 1, 2, 1, 1, 1, 1, 5, 7, 4, 1, 1, 8, 3, 1, 1, 4, 1, 5, 3, 9, 1, 1, 1, 3, 7, 3, 1, 2, 5, 4, 4, 10, 1, 3, 1, 11, 1, 1, 2, 5, 1, 7, 9, 1, 1, 2, 1, 12, 3, 4, 5, 2, 1, 3, 1, 13, 1, 1, 7

Offset: 1

Gus Wiseman, Jul 26 2019

This is a dual form of the average of an integer partition specified by its Heinz number: A326567/A326568.

			The sequence of fractions begins: 0, 1, 1, 2, 1, 3/2, 1, 3, 2, 4/3, 1, 2, 1, 5/4, 5/3, 4, 1, 5/2, 1, 5/3.

Positions of 1's are A326836.
Numerators are A326839.
Cf. A001222, A047993, A056239, A061395, A112798, A316413.
Cf. A326567/A326568, A326836, A326845, A326848, A326850.

primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
Denominator[Table[Total[primeMS[n]]/Max@@primeMS[n],{n,100}]]

A340827 Number of strict integer partitions of n into divisors of n whose length also divides n.

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 5, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 5, 1, 1, 1, 3, 1, 2, 1, 1, 1, 1, 1, 6, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 25, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 18, 1, 1, 1, 1, 1, 2, 1, 3, 1, 1, 1, 17, 1, 1, 1, 1, 1, 14, 1, 1, 1, 1, 1, 12, 1, 1, 1, 3, 1, 2, 1, 1, 1

Offset: 1

Gus Wiseman, Feb 01 2021

nonn

The first element not in A326715 that is however a Heinz number of these partitions is 273.

			The a(n) partitions for n = 6, 12, 24, 90, 84:
  6       12        24            90                      84
  3,2,1   6,4,2     12,8,4        45,30,15                42,28,14
          6,3,2,1   12,6,4,2      45,30,9,5,1             42,21,14,7
                    12,8,3,1      45,18,15,9,3            42,28,12,2
                    8,6,4,3,2,1   45,30,10,3,2            42,28,6,4,3,1
                                  45,18,15,10,2           42,28,7,4,2,1
                                  45,30,6,5,3,1           42,14,12,7,6,3
                                  45,30,9,3,2,1           42,21,12,4,3,2
                                  45,15,10,9,6,5          42,21,12,6,2,1
                                  45,18,10,9,5,3          42,21,14,4,2,1
                                  45,18,10,9,6,2          28,21,14,12,6,3
                                  45,18,15,6,5,1          28,21,14,12,7,2
                                  45,18,15,9,2,1          42,21,7,6,4,3,1
                                  30,18,15,10,6,5,3,2,1   42,14,12,7,4,3,2
                                                          42,14,12,7,6,2,1
                                                          28,21,14,12,4,3,2
                                                          28,21,14,12,6,2,1

David A. Corneth, Table of n, a(n) for n = 1..10000 (first 2519 terms from Antti Karttunen)
Antti Karttunen, Scheme program for computing this sequence

Note: A-numbers of Heinz-number sequences are in parentheses below.
The non-strict case is A326842 (A326847).
A018818 = partitions using divisors (A326841).
A047993 = balanced partitions (A106529).
A067538 = partitions whose length/maximum divides sum (A316413/A326836).
A072233 = partitions by sum and length, with strict case A008289.
A102627 = strict partitions whose length divides sum.
A326850 = strict partitions whose maximum part divides sum.
A326851 = strict partitions w/ length and max dividing sum.
A340828 = strict partitions w/ length divisible by max.
A340829 = strict partitions w/ Heinz number divisible by sum.
A340830 = strict partitions w/ parts divisible by length.
Cf. A064173, A143773 (A316428), A168659, A326843 (A326837), A326852, A330950 (A324851), A340851, A340853.

Table[Length[Select[IntegerPartitions[n,All,Divisors[n]],UnsameQ@@#&&Divisible[n,Length[#]]&]],{n,30}]

A340827(n, divsleft=List(divisors(n)), rest=n, len=0) = if(rest<=0, !rest && !(n%len), my(s=0, d); forstep(i=#divsleft, 1, -1, d = divsleft[i]; listpop(divsleft,i); if(rest>=d, s += A340827(n, divsleft, rest-d, 1+len))); (s)); \\ Antti Karttunen, Feb 22 2023

;; See the Links-section. - Antti Karttunen, Feb 22 2023

Data section extended up to a(105) by Antti Karttunen, Feb 22 2023

A381542 Numbers > 1 whose greatest prime index equals their greatest prime multiplicity.

Original entry on oeis.org

2, 9, 12, 18, 36, 40, 112, 120, 125, 135, 200, 250, 270, 336, 352, 360, 375, 500, 540, 560, 567, 600, 675, 750, 784, 832, 1000, 1008, 1056, 1080, 1125, 1134, 1350, 1500, 1680, 1760, 1800, 2176, 2250, 2268, 2352, 2401, 2464, 2496, 2673, 2700, 2800, 2835, 3000

Offset: 1

Gus Wiseman, Mar 24 2025

nonn

A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798, sum A056239.

			The terms together with their prime indices begin:
     2: {1}
     9: {2,2}
    12: {1,1,2}
    18: {1,2,2}
    36: {1,1,2,2}
    40: {1,1,1,3}
   112: {1,1,1,1,4}
   120: {1,1,1,2,3}
   125: {3,3,3}
   135: {2,2,2,3}
   200: {1,1,1,3,3}
   250: {1,3,3,3}
   270: {1,2,2,2,3}
   336: {1,1,1,1,2,4}
   352: {1,1,1,1,1,5}
   360: {1,1,1,2,2,3}

Counting partitions by the LHS gives A008284, rank statistic A061395.
Counting partitions by the RHS gives A091602, rank statistic A051903.
For length instead of maximum we have A106529, counted by A047993 (balanced partitions).
For number of distinct factors instead of max index we have A212166, counted by A239964.
Partitions of this type are counted by A240312.
Including number of distinct parts gives A381543, counted by A382302.
A000005 counts divisors.
A000040 lists the primes, differences A001223.
A001222 counts prime factors, distinct A001221.
A051903 gives greatest prime exponent, least A051904.
A055396 gives least prime index, greatest A061395.
A056239 adds up prime indices, row sums of A112798.
A122111 represents partition conjugation in terms of Heinz numbers.
A381544 counts partitions without more ones than any other part, ranks A381439.
Cf. A000720, A047966, A048767, A130091, A317090, A381632.

Select[Range[2,1000],PrimePi[FactorInteger[#][[-1,1]]]==Max@@FactorInteger[#][[All,2]]&]

A061395(a(n)) = A051903(a(n)).

A383090 Number of integer partitions of n having more than one permutation with all equal run-lengths.

Original entry on oeis.org

0, 0, 0, 1, 1, 2, 4, 5, 9, 14, 20, 28, 43, 55, 77, 107, 141, 183, 244, 312, 411, 521, 664, 837, 1069, 1328, 1667, 2069, 2578, 3166, 3929, 4791, 5895, 7168, 8749, 10594, 12883, 15500, 18741, 22493, 27069, 32334, 38760, 46133, 55065, 65367, 77686, 91905, 108927, 128431, 151674

Offset: 0

Gus Wiseman, Apr 19 2025

nonn

			The partition (3322221) has 3 permutations with all equal run-lengths: (2323212), (2321232), (2123232), so is counted under a(15).
The partition (3322111111) has 2 permutations with all equal run-lengths: (1133112211), (1122113311), so is counted under a(16).
The a(3) = 1 through a(9) = 14 partitions:
  (21)  (31)  (32)  (42)    (43)    (53)     (54)
              (41)  (51)    (52)    (62)     (63)
                    (321)   (61)    (71)     (72)
                    (2211)  (421)   (431)    (81)
                            (3211)  (521)    (432)
                                    (3221)   (531)
                                    (3311)   (621)
                                    (4211)   (3321)
                                    (32111)  (4221)
                                             (4311)
                                             (5211)
                                             (32211)
                                             (42111)
                                             (222111)

For no choices we have A382915, ranks A382879.
For at least one choice we have A383013, for run-sums A383098, ranks A383110.
Partitions of this type are ranked by A383089 = positions of terms > 1 in A382857.
The complement is A383091, counted by A383092.
For a unique choice we have A383094, ranks A383112.
The complement for run-sums is A383095 + A383096, ranks A383099 \/ A383100.
For run-sums we have A383097, ranked by A383015 = positions of terms > 1 in A382877.
For distinct instead of equal run-lengths we have A383111, ranks A383113.
Cf. A047966, A072774, A098859, A304442, A100471, A100881, A100882, A100883.
A000041 counts integer partitions, strict A000009.
A008284 counts partitions by length, strict A008289.
A239455 counts Look-and-Say partitions, ranks A351294, conjugate A381432.
A329738 counts compositions with equal run-lengths, ranks A353744.
A351293 counts non-Look-and-Say partitions, ranks A351295, conjugate A381433.
Cf. A047993, A237984, A329739, A381541, A381871, A382076, A382771.

Table[Length[Select[IntegerPartitions[n], Length[Select[Permutations[#], SameQ@@Length/@Split[#]&]]>1&]],{n,0,15}]

The complement is counted by A383094 + A382915, ranks A383112 \/ A382879.

More terms from Bert Dobbelaere, Apr 26 2025

A384881 Triangle read by rows where T(n,k) is the number of integer partitions of n with k maximal runs of consecutive parts decreasing by 1.

Original entry on oeis.org

1, 0, 1, 0, 1, 1, 0, 2, 0, 1, 0, 1, 3, 0, 1, 0, 2, 2, 2, 0, 1, 0, 2, 3, 3, 2, 0, 1, 0, 2, 5, 3, 2, 2, 0, 1, 0, 1, 8, 4, 4, 2, 2, 0, 1, 0, 3, 5, 10, 4, 3, 2, 2, 0, 1, 0, 2, 9, 9, 9, 5, 3, 2, 2, 0, 1, 0, 2, 11, 13, 9, 9, 4, 3, 2, 2, 0, 1

Offset: 0

Gus Wiseman, Jun 25 2025

			The partition (5,4,2,1,1) has maximal runs ((5,4),(2,1),(1)) so is counted under T(13,3) = 23.
Row n = 9 counts the following partitions:
  9    63    333    6111    33111   411111   3111111   111111111
  54   72    441    22221   51111   2211111  21111111
  432  81    522    42111   222111
       621   531    321111
       3321  711
             3222
             4221
             4311
             5211
             32211
Triangle begins:
  1
  0  1
  0  1  1
  0  2  0  1
  0  1  3  0  1
  0  2  2  2  0  1
  0  2  3  3  2  0  1
  0  2  5  3  2  2  0  1
  0  1  8  4  4  2  2  0  1
  0  3  5 10  4  3  2  2  0  1
  0  2  9  9  9  5  3  2  2  0  1
  0  2 11 13  9  9  4  3  2  2  0  1
  0  2 13 15 17  8 10  4  3  2  2  0  1
  0  2 14 23 16 17  8  9  4  3  2  2  0  1
  0  2 16 26 26 19 16  9  9  4  3  2  2  0  1
  0  4 13 37 32 26 19 16  8  9  4  3  2  2  0  1

John Tyler Rascoe, Rows n = 0..100, flattened

Row sums are A000041.
Column k = 1 is A001227.
For distinct parts instead of maximal runs we have A116608.
The strict case appears to be A116674.
For anti-runs instead of runs we have A268193.
Partitions with distinct runs of this type are counted by A384882, gapless A384884.
For prime indices see A385213, A287170, A066205, A356229.
A007690 counts partitions with no singletons, complement A183558.
A034296 counts flat or gapless partitions, ranks A066311 or A073491.
Cf. A000009, A000217, A008284, A047966, A047993, A098859, A325325, A375136, A384887.

Table[Length[Select[IntegerPartitions[n],Length[Split[#,#1==#2+1&]]==k&]],{n,0,10},{k,0,n}]

tri(n) = {(n*(n+1)/2)}
B_list(N) = {my(v = vector(N, i, 0)); v[1] = q*t; for(m=2,N, v[m] = t * (q^tri(m) + sum(i=1,m-1, q^tri(i) * v[m-i] * (q^((m-i)*(i-1))/(1 - q^(m-i)) - q^((m-i)*i) + O('q^(N-tri(i)+1)))))); v}
A_qt(max_row) = {my(N = max_row+1, B = B_list(N), g = 1 + sum(m=1,N, B[m]/(1 - q^m)) + O('q^(N+1))); vector(N, n, Vecrev(polcoeff(g, n-1)))} \\ John Tyler Rascoe, Aug 18 2025

G.f.: 1 + Sum_{m>0} B(m,q,t)/(1 - q^m) where B(m,q,t) = t * (q^tri(m) + Sum_{i=1..m-1} q^tri(i) * B(m-i,q,t) * ((q^((m-i)*(i-1))/(1 - q^(m-i))) - q^((m-i)*i))) and tri(n) = A000217(n). - John Tyler Rascoe, Aug 18 2025

A029895 Number of partitions of floor(n^2/2) with at most n parts and maximal height n.

Original entry on oeis.org

1, 1, 2, 3, 8, 20, 58, 169, 526, 1667, 5448, 18084, 61108, 208960, 723354, 2527074, 8908546, 31630390, 113093022, 406680465, 1470597342, 5342750699, 19499227828, 71442850111, 262754984020, 969548468960, 3589093760726, 13323571588607, 49596793134484

Offset: 0

torsten.sillke(AT)lhsystems.com

nonn

This is the maximum value for the distribution of partitions of (0 .. n^2) that fit in an n X n box; assuming the peak of a normal distribution 1/sqrt(variance*2*Pi) approximates to these partitions and using A068606 suggests C(2n,n)*sqrt(6/(Pi*n^2*(2n+1))) could be an approximation [within 0.3% for a(100)=88064925963069745337300842293630181021718294488842002448]; using Stirling's approximation gives the simpler (sqrt(3)/Pi)*4^n/n^2 [about 0.6% away for a(100)] though experimentation suggests that something like (sqrt(3)/Pi)*4^n/(n^2+3n/5+1/5) is closer [about 0.0001% away for a(100)]. - Henry Bottomley, Mar 13 2002

Bisection of A277218 with even indexes. - Vladimir Reshetnikov, Oct 09 2016

			a(4)=8 because the partitions of Floor[4^2 /2] that fit inside a 4 X 4 box are {4, 4}, {4, 3, 1}, {4, 2, 2}, {4, 2, 1, 1}, {3, 3, 2}, {3, 3, 1, 1}, {3, 2, 2, 1}, {2, 2, 2, 2}.

R. A. Brualdi, H. J. Ryser, Combinatorial Matrix Theory, Cambridge Univ. Press, 1992.

Vladimir Reshetnikov, Table of n, a(n) for n = 0..190
Eric W. Weisstein, q-Binomial Coefficient
Wikipedia, q-binomial

Cf. A000569, A004250, A004251, A029889, A047993, diagonal of A067059, A068607, A277218.

Table[Coefficient[Expand[FunctionExpand[QBinomial[2 n, n, q]]], q, Floor[n^2/2]], {n, 0, 30}] (* Vladimir Reshetnikov, Oct 09 2016 *)

{a(n)=if(n==0,1,polcoeff(prod(i=1,n,(1-q^(n+i))/(1-q^i)),n^2\2,q))} \\ Paul D. Hanna, Feb 15 2007

Calculated using Cor. 6.3.3, Th. 6.3.6, Cor. 6.2.5 of Brualdi-Ryser. Table[T[Floor[n^2/2], n, n], {n, 0, 36}] with T[ ] defined as in A047993. a(n)=A067059(n, n).

a(n) equals the central coefficient of q in the central q-binomial coefficients for n>0: a(n) = [q^([n^2/2])] Product_{i=1..n} (1-q^(n+i))/(1-q^i), with a(0)=1. - Paul D. Hanna, Feb 15 2007

More terms and comments from Wouter Meeussen, Aug 14 2001
Edited by Henry Bottomley, Feb 17 2002
a(27)-a(28) from Alois P. Heinz, Oct 31 2018

cp's OEIS Frontend

A383094 Number of integer partitions of n having exactly one permutation with all equal run-lengths.

Views

Author

Keywords

Examples

Crossrefs

Programs

Mathematica

Extensions

A326846 Length times maximum of the integer partition with Heinz number n.

Views

Author

Keywords

Comments

Links

Crossrefs

Programs

Mathematica

PARI

Formula

Extensions

A383508 Number of integer partitions of n that are both Look-and-Say and section-sum partitions.

Views

Author

Keywords

Comments

Examples

Crossrefs

Programs

Mathematica

A326839 Numerator of A056239(n)/A061395(n) where A056239 is sum of prime indices and A061395 is maximum prime index.

Views

Author

Keywords

Comments

Examples

Crossrefs

Programs

Mathematica

A326840 Denominator of A056239(n)/A061395(n).

Views

Author

Keywords

Comments

Examples

Crossrefs

Programs

Mathematica

A340827 Number of strict integer partitions of n into divisors of n whose length also divides n.

Views

Author

Keywords

Comments

Examples

Links

Crossrefs

Programs

Mathematica

PARI

Scheme

Extensions

A381542 Numbers > 1 whose greatest prime index equals their greatest prime multiplicity.

Views

Author

Keywords

Comments

Examples

Crossrefs

Programs

Mathematica

Formula

A383090 Number of integer partitions of n having more than one permutation with all equal run-lengths.

Views

Author

Keywords

Examples

Crossrefs

Programs

Mathematica