A116598 -id:A116598 - cp's OEIS frontend

A366840 Sum of odd prime factors of n, counted with multiplicity.

0, 0, 3, 0, 5, 3, 7, 0, 6, 5, 11, 3, 13, 7, 8, 0, 17, 6, 19, 5, 10, 11, 23, 3, 10, 13, 9, 7, 29, 8, 31, 0, 14, 17, 12, 6, 37, 19, 16, 5, 41, 10, 43, 11, 11, 23, 47, 3, 14, 10, 20, 13, 53, 9, 16, 7, 22, 29, 59, 8, 61, 31, 13, 0, 18, 14, 67, 17, 26, 12, 71, 6

Offset: 1

Gus Wiseman, Oct 27 2023

Contains all positive integers except 1, 2, 4.

			The prime factors of 60 are {2,2,2,3,5}, of which the odd factors are {3,5}, so a(60) = 8.

The compound version is A001414, triangle A331416.
For count instead of sum we have A087436, even version A007814.
Odd-indexed terms are A100005.
Positions of odd terms are A335657, even A036349.
For prime indices we have A366528, triangle A113685 (without zeros A365067)
The even version is A366839 = 2*A001511.
The partition triangle for this statistic is A366851, even version A116598.
A019507 lists numbers with (even factor sum) = (odd factor sum).
A066207 lists numbers with all even prime indices, counted by A035363.
A112798 lists prime indices, reverse A296150, length A001222, sum A056239.
A162641 counts even prime exponents, odd A162642.
A239261 counts partitions with (sum of odd parts) = (sum of even parts).
A257992 counts even prime indices, odd A257991.
Cf. A000009, A066208, A113686, A174713, A258117, A325698, A366531, A366850.

Table[Total[Times@@@DeleteCases[If[n==1,{}, FactorInteger[n]],{2,_}]],{n,100}]

a(n) = my(f=factor(n), j=if(n%2, 1, 2)); sum(i=j, #f~, f[i,1]*f[i,2]); \\ Michel Marcus, Oct 30 2023

a(n) = A100006(n) - A366839(n).
a(2n) = a(n).
a(2n-1) = A001414(2n-1) = A100005(n).
Completely additive with a(2^e) = 0 and a(p^e) = e*p for an odd prime p. - Amiram Eldar, Nov 03 2023

A382303 Number of integer partitions of n with exactly as many ones as the next greatest multiplicity.

Original entry on oeis.org

0, 0, 0, 1, 1, 1, 3, 2, 4, 5, 8, 6, 15, 13, 19, 25, 33, 36, 54, 58, 80, 96, 122, 141, 188, 217, 274, 326, 408, 474, 600, 695, 859, 1012, 1233, 1440, 1763, 2050, 2475, 2899, 3476, 4045, 4850, 5630, 6695, 7797, 9216, 10689, 12628, 14611, 17162, 19875, 23253

Offset: 0

Gus Wiseman, Mar 24 2025

nonn

			The a(3) = 1 through a(10) = 8 partitions:
  (21)  (31)  (41)  (51)    (61)   (71)    (81)      (91)
                    (321)   (421)  (431)   (531)     (541)
                    (2211)         (521)   (621)     (631)
                                   (3311)  (32211)   (721)
                                           (222111)  (4321)
                                                     (4411)
                                                     (33211)
                                                     (42211)

First differences of A241131, ranks A360013 = 2*A360015 (if we prepend 1).
The Heinz numbers of these partitions are A360014.
Equal case of A381544 (ranks A381439).
A000041 counts integer partitions, strict A000009.
A008284 counts partitions by length, strict A008289.
A047993 counts partitions with max = length, ranks A106529.
A091602 counts partitions by the greatest multiplicity, rank statistic A051903.
A116598 counts ones in partitions, rank statistic A007814.
A239964 counts partitions with max multiplicity = length, ranks A212166.
A240312 counts partitions with max = max multiplicity, ranks A381542.
A382302 counts partitions with max = max multiplicity = distinct length, ranks A381543.
Cf. A047966, A051904, A091605, A116861, A237984, A239455, A362608, A363724, A381079, A381437, A381438.

Table[Length[Select[IntegerPartitions[n],Count[#,1]==Max@@Length/@Split[DeleteCases[#,1]]&]],{n,0,30}]

A366851 Irregular triangle read by rows where T(n,k) is the number of integer partitions of n such that the sum of primes indexed by all parts greater than one is k.

Original entry on oeis.org

1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 2, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 2, 2, 2, 3, 2, 0, 2, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 2, 2, 2, 3, 3, 2, 2, 2, 2, 1, 1, 0, 0, 1

Offset: 0

Gus Wiseman, Nov 01 2023

To illustrate the definition, the sum of primes indexed by all parts greater than one of the partition (5,2,2,1) is prime(5) + prime(2) + prime(2) = 17.

			Triangle begins:
  1
  1
  1 0 0 1
  1 0 0 1 0 1
  1 0 0 1 0 1 1 1
  1 0 0 1 0 1 1 1 1 0 0 1
  1 0 0 1 0 1 1 1 1 1 2 1 0 1
  1 0 0 1 0 1 1 1 1 1 2 2 1 1 1 0 0 1
  1 0 0 1 0 1 1 1 1 1 2 2 2 3 2 0 2 1 0 1
  1 0 0 1 0 1 1 1 1 1 2 2 2 3 3 2 2 2 2 1 1 0 0 1
  1 0 0 1 0 1 1 1 1 1 2 2 2 3 3 3 4 4 2 3 2 0 3 1 0 0 0 0 0 1
  1 0 0 1 0 1 1 1 1 1 2 2 2 3 3 3 4 5 4 4 3 3 3 2 3 0 1 0 0 1 0 1
The T(8,13) = 3 partitions are: (6,1,1), (4,2,2), (3,3,2).
The T(10,17) = 4 partitions are: (7,1,1,1), (5,2,2,1), (4,4,2), (4,3,3).

Row lengths are A055670.
Columns appear to converge to A099773.
A bisected even version is A116598 (counts partitions by number of 1's).
Counting all parts (not just > 1) gives A331416, shifted A331385.
A000041 counts integer partitions, strict A000009 (also into odds).
A113685 counts partitions by sum of odd parts, rank statistic A366528.
A330953 counts partitions with Heinz number divisible by sum of primes.
A331381 counts partitions with (product)|(sum of primes), equality A331383.
Cf. A000837, A014689, A113686, A239261, A331417, A331418, A365067, A366842.

Table[Length[Select[IntegerPartitions[n], Total[Select[Prime/@#,OddQ]]==k&]], {n,0,10}, {k,0,If[n<=1,0,Prime[n]]}]

A194711 Triangle read by rows: T(n,k) = number of partitions or zones in the last section of the set of partitions of n that contains k as a part.

Original entry on oeis.org

1, 1, 1, 2, 0, 1, 3, 1, 0, 1, 5, 1, 1, 0, 1, 7, 2, 1, 1, 0, 1, 11, 2, 2, 1, 1, 0, 1, 15, 4, 2, 1, 1, 1, 0, 1

Offset: 1

Omar E. Pol, Feb 10 2012

It appears that row n lists A000041(n)-1 together with the row n-2 of the triangle A116598, if n >= 2.

			Triangle begins:
1,
1, 1,
2, 0, 1,
3, 1, 0, 1,
5, 1, 1, 0, 1,
7, 2, 1, 1, 0, 1,
11, 2, 2, 1, 1, 0, 1,
15, 4, 2, 1, 1, 1, 0, 1,

Column 1 is A000041. Columns >= 2 are A002865.

Cf. A027293, A116598, A135010, A138121, A182703, A194812.

A194799 Triangle read by rows: T(n,k) = number of partitions of n that are formed by k sections, k >= 1.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 2, 1, 1, 1, 4, 2, 2, 1, 1, 1, 4, 4, 2, 2, 1, 1, 1, 7, 4, 4, 2, 2, 1, 1, 1, 8, 7, 4, 4, 2, 2, 1, 1, 1, 12, 8, 7, 4, 4, 2, 2, 1, 1, 1, 14, 12, 8, 7, 4, 4, 2, 2, 1, 1, 1, 21, 14, 12, 8, 7, 4, 4, 2, 2, 1, 1, 1, 24, 21, 14

Offset: 1

Omar E. Pol, Jan 30 2012

Also triangle read by rows in which row n lists the first k terms of A187219 in reverse order. For more information see A135010.

			Triangle begins:
1,
1,1,
1,1,1,
2,1,1,1,
2,2,1,1,1,
4,2,2,1,1,1,
4,4,2,2,1,1,1,
7,4,4,2,2,1,1,1,
8,7,4,4,2,2,1,1,1,
12,8,7,4,4,2,2,1,1,1,
14,12,8,7,4,4,2,2,1,1,1,
21,14,12,8,7,4,4,2,2,1,1,1

Columns are A187219. Row sums give A000041, n >= 1.

Cf. A002865, A116598, A135010, A138121, A182748, A186114, A193870, A194436-A194438, A194446.

A300185 Irregular triangle read by rows: T(n, {j,k}) is the number of partitions of n that have exactly j parts equal to k; 1 <= j <= n, 1 <= k <= n.

Original entry on oeis.org

1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 2, 1, 1, 0, 1, 2, 1, 0, 0, 0, 2, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 2, 2, 1, 1, 0, 1, 3, 1, 1, 0, 0, 0, 2, 1, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 4, 2, 2, 1, 1, 0, 1, 4, 2, 1, 0, 0, 0, 0, 4, 1, 0, 0, 0, 0, 0, 3, 0

Offset: 1

J. Stauduhar, Feb 27 2018

Row sums = A027293.
If superfluous zeros are removed from the right side of each row, the row lengths = 1,2,1,3,1,1,4,2,... = A010766.
Sum of each N X N block of rows = 1,2,4,7,12,19,... = A000070.
The sum of the partitions of n that are over-counted in each block of N x N rows = A000070(n) - A000041(n) = A058884(n), n >= 1.
Concatenation of first row from each N X N block = A116598.
As noted by Joerg Arndt in A116598, the first row from each N X N block in reverse converges to A002865.  Two sequences emerge from alternating second rows in reverse:  for 2n, converges to even-indexed terms in A027336, and for 2n+1, converges to odd-indexed terms in A027336.
Counting the rows in each N X N block where columns j=2 > 0 and j=3 through j=n are all zeros produces A008615(n), n > 0.

			      \ j  1 2 3 4 5
     k
n
1:   1     1
2:   1     0 1
     2     1 0
3:   1     1 0 1
     2     1 0 0
     3     1 0 0
4:   1     1 1 0 1
     2     1 1 0 0
     3     1 0 0 0
     4     1 0 0 0
5:   1     2 1 1 0 1
     2     2 1 0 0 0
     3     2 0 0 0 0
     4     1 0 0 0 0
     5     1 0 0 0 0
.
.
.

J. Stauduhar, Table of n, a(n) for n = 1..10000
Jerome Kelleher and Barry O'Sullivan, Generating All Partitions: A Comparison Of Two Encodings, arXiv:0909.2331 [cs.DS], 2009-2014.
J. Stauduhar, Original Python program.

Cf. A000041, A000070, A008615, A010766, A027293, A027336, A058884, A116598.

Array[With[{s = IntegerPartitions[#]}, Table[Count[Map[Count[#, k] &, s], j], {k, #}, {j, #}]] &, 7] // Flatten (* Michael De Vlieger, Feb 28 2018 *)

Python
```
# See Stauduhar link.
```

A366841 Least positive integer whose odd prime factors sum to n, starting with n = 5.

Original entry on oeis.org

5, 9, 7, 15, 27, 21, 11, 35, 13, 33, 105, 39, 17, 65, 19, 51, 195, 57, 23, 95, 171, 69, 285, 115, 29, 161, 31, 87, 483, 93, 261, 155, 37, 217, 465, 111, 41, 185, 43, 123, 555, 129, 47, 215, 387, 141, 645, 235, 53, 329, 705, 159, 987, 265, 59, 371, 61, 177

Offset: 5

Gus Wiseman, Oct 27 2023

nonn

All terms are odd.

It seems that all composite terms not divisible by 3 form a supersequence of A292081. - Ivan N. Ianakiev, Oct 30 2023

			The terms together with their prime factors (which sum to n) begin:
    5 = 5
    9 = 3*3
    7 = 7
   15 = 3*5
   27 = 3*3*3
   21 = 3*7
   11 = 11
   35 = 5*7
   13 = 13
   33 = 3*11
  105 = 3*5*7

Michel Marcus, Table of n, a(n) for n = 5..1000

This is the odd case of A056240.
Positions of first appearances in A366840 (sum of odd prime factors).
The partition triangle for this statistic is A366851, even A116598.
A001414 adds up prime factors, triangle A331416.
A019507 lists numbers with (even factor sum) = (odd factor sum).
A027746 lists prime factors, length A001222.
A087436 counts odd prime factors, even A007814.
A366528 adds up odd prime indices, triangle A113685 (without zeros A365067).
Cf. A031368, A036349, A056239, A066208, A100005, A112798, A239261, A257991, A335657, A366839.

nn=1000;
w=Table[Total[Times@@@DeleteCases[If[n==1,{},FactorInteger[n]],{2,_}]],{n,nn}];
spnm[y_]:=Max@@Select[Union[y],Function[i,Union[Select[y,#<=i&]]==Range[i]]];
Table[Position[w,k][[1,1]],{k,5,spnm[Join[{1,2,3,4},Take[w,nn]/.(0->1)]]}]

f(n) = my(f=factor(n), j=if (n%2, 1, 2)); sum(i=j, #f~, f[i,1]*f[i,2]); \\ A366840
a(n) = my(k=1); while (f(k) != n, k++); k; \\ Michel Marcus, Nov 02 2023

A382526 Number of integer partitions of n with fewer ones than greatest multiplicity.

Original entry on oeis.org

0, 0, 1, 1, 2, 3, 4, 6, 9, 12, 16, 24, 30, 41, 56, 72, 94, 124, 158, 205, 262, 331, 419, 531, 663, 829, 1033, 1281, 1581, 1954, 2393, 2936, 3584, 4366, 5300, 6433, 7764, 9374, 11277, 13548, 16225, 19425, 23166, 27623, 32842, 39004, 46212, 54719, 64610, 76251

Offset: 0

Gus Wiseman, Apr 05 2025

nonn

			The a(2) = 1 through a(9) = 12 partitions:
  (2)  (3)  (4)   (5)    (6)    (7)     (8)      (9)
            (22)  (32)   (33)   (43)    (44)     (54)
                  (221)  (42)   (52)    (53)     (63)
                         (222)  (322)   (62)     (72)
                                (331)   (332)    (333)
                                (2221)  (422)    (432)
                                        (2222)   (441)
                                        (3221)   (522)
                                        (22211)  (3222)
                                                 (3321)
                                                 (4221)
                                                 (22221)

The complement (greater than or equal to) is A241131 except first, ranks A360015.
The opposite version (greater than) is A241131 shifted except first, ranks A360013.
These partitions have ranks A382856, complement A360015.
The weak version (less than or equal to) is A381544, ranks A381439.
For equality we have A382303, ranks A360014.
A000041 counts integer partitions, strict A000009.
A008284 counts partitions by length, strict A008289.
A047993 counts partitions with max part = length, ranks A106529.
A091602 counts partitions by the greatest multiplicity, rank statistic A051903.
A116598 counts ones in partitions, rank statistic A007814.
A239964 counts partitions with max multiplicity = length, ranks A212166.
A240312 counts partitions with max part = max multiplicity, ranks A381542.
A382302 counts partitions with max = max multiplicity = distinct length, ranks A381543.
Cf. A047966, A091605, A116861, A232697, A237984, A362608, A363724, A381079, A381437, A381438.

Table[Length[Select[IntegerPartitions[n],Count[#,1]

A382856 Numbers whose prime indices do not have a mode of 1.

Original entry on oeis.org

1, 3, 5, 7, 9, 11, 13, 15, 17, 18, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 50, 51, 53, 54, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 89, 90, 91, 93, 95, 97, 98, 99, 101, 103, 105, 107, 108, 109, 111, 113, 115

Offset: 1

Gus Wiseman, Apr 07 2025

nonn

			The terms together with their prime indices begin:
   1: {}
   3: {2}
   5: {3}
   7: {4}
   9: {2,2}
  11: {5}
  13: {6}
  15: {2,3}
  17: {7}
  18: {1,2,2}
  19: {8}
  21: {2,4}
  23: {9}
  25: {3,3}
  27: {2,2,2}

The case of non-unique mode is A024556.
The complement is A360015 except first.
Partitions of this type are are counted by A382526 except first, complement A241131.
A091602 counts partitions by the greatest multiplicity, rank statistic A051903.
A112798 lists prime indices, length A001222, sum A056239.
A116598 counts ones in partitions, rank statistic A007814.
A240312 counts partitions with max part = max multiplicity, ranks A381542.
A362611 counts modes in prime indices, triangle A362614.
For co-mode see A359178, A362613, A364061 (A364062), A364158 (A364159).
Cf. A000265, A002865, A106529, A327473, A327476, A362605, A363486, A356862, A360013, A360014, A381437.

prix[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
Select[Range[100],FreeQ[Commonest[prix[#]],1]&]

cp's OEIS Frontend

A366840 Sum of odd prime factors of n, counted with multiplicity.

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A382303 Number of integer partitions of n with exactly as many ones as the next greatest multiplicity.

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A366851 Irregular triangle read by rows where T(n,k) is the number of integer partitions of n such that the sum of primes indexed by all parts greater than one is k.

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A194711 Triangle read by rows: T(n,k) = number of partitions or zones in the last section of the set of partitions of n that contains k as a part.

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A194799 Triangle read by rows: T(n,k) = number of partitions of n that are formed by k sections, k >= 1.

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A300185 Irregular triangle read by rows: T(n, {j,k}) is the number of partitions of n that have exactly j parts equal to k; 1 <= j <= n, 1 <= k <= n.

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A366841 Least positive integer whose odd prime factors sum to n, starting with n = 5.

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A382526 Number of integer partitions of n with fewer ones than greatest multiplicity.

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A382856 Numbers whose prime indices do not have a mode of 1.

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