A239261
Number of partitions of n having (sum of odd parts) = (sum of even parts).
Original entry on oeis.org
1, 0, 0, 0, 1, 0, 0, 0, 4, 0, 0, 0, 12, 0, 0, 0, 30, 0, 0, 0, 70, 0, 0, 0, 165, 0, 0, 0, 330, 0, 0, 0, 704, 0, 0, 0, 1380, 0, 0, 0, 2688, 0, 0, 0, 4984, 0, 0, 0, 9394, 0, 0, 0, 16665, 0, 0, 0, 29970, 0, 0, 0, 52096, 0, 0, 0, 90090, 0, 0, 0, 152064, 0, 0, 0
Offset: 0
a(8) counts these 4 partitions: 431, 41111, 3221, 221111.
From _Gus Wiseman_, Oct 24 2023: (Start)
The a(0) = 1 through a(12) = 12 partitions:
() . . . (211) . . . (431) . . . (633)
(3221) (651)
(41111) (4332)
(221111) (5421)
(33222)
(52221)
(63111)
(432111)
(3222111)
(6111111)
(42111111)
(222111111)
(End)
The LHS (sum of odd parts) is counted by
A113685.
The RHS (sum of even parts) is counted by
A113686.
Without all the zeros we have a(4n) =
A249914(n).
The strict case (without zeros) is
A255001.
-
z = 40; p[n_] := p[n] = IntegerPartitions[n]; f[t_] := f[t] = Length[t]
t1 = Table[f[Select[p[n], 2 Total[Select[#, OddQ]] < n &]], {n, z}] (* A239259 *)
t2 = Table[f[Select[p[n], 2 Total[Select[#, OddQ]] <= n &]], {n, z}] (* A239260 *)
t3 = Table[f[Select[p[n], 2 Total[Select[#, OddQ]] == n &]], {n, z}] (* A239261 *)
t4 = Table[f[Select[p[n], 2 Total[Select[#, OddQ]] > n &]], {n, z}] (* A239262 *)
t5 = Table[f[Select[p[n], 2 Total[Select[#, OddQ]] >= n &]], {n, z}] (* A239263 *)
(* Peter J. C. Moses, Mar 12 2014 *)
A240021
Number T(n,k) of partitions of n into distinct parts, where k is the difference between the number of odd parts and the number of even parts; triangle T(n,k), n>=0, read by rows.
Original entry on oeis.org
1, 1, 1, 1, 1, 1, 0, 0, 1, 2, 1, 1, 1, 0, 1, 1, 1, 3, 1, 1, 1, 0, 2, 2, 2, 4, 1, 0, 1, 2, 1, 1, 4, 2, 4, 5, 1, 1, 1, 1, 2, 1, 2, 6, 3, 1, 6, 6, 1, 2, 2, 1, 3, 1, 5, 9, 3, 2, 9, 7, 2, 4, 3, 2, 3, 2, 8, 12, 4, 0, 1, 4, 12, 8, 3, 7, 4, 3, 4, 3, 14, 16, 4, 1, 1, 7, 16, 9, 6, 11, 5, 1, 4, 4, 6, 20, 20, 5, 2, 2
Offset: 0
T(12,-3) = 1: [6,4,2].
T(12,-2) = 2: [10,2], [8,4].
T(12,-1) = 1: [12].
T(12,0) = 2: [6,3,2,1], [5,4,2,1].
T(12,1) = 6: [9,2,1], [8,3,1], [7,4,1], [7,3,2], [6,5,1], [5,4,3].
T(12,2) = 3: [11,1], [9,3], [7,5].
T(13,-1) = 6: [10,2,1], [8,4,1], [8,3,2], [7,4,2], [6,5,2], [6,4,3].
T(14,-2) = 3: [12,2], [10,4], [8,6].
Triangle T(n,k) begins:
: n\k : -3 -2 -1 0 1 2 3 ...
+-----+--------------------------
: 0 : 1
: 1 : 1
: 2 : 1
: 3 : 1, 1
: 4 : 1, 0, 0, 1
: 5 : 2, 1
: 6 : 1, 1, 0, 1, 1
: 7 : 1, 3, 1
: 8 : 1, 1, 0, 2, 2
: 9 : 2, 4, 1, 0, 1
: 10 : 2, 1, 1, 4, 2
: 11 : 4, 5, 1, 1, 1
: 12 : 1, 2, 1, 2, 6, 3
: 13 : 1, 6, 6, 1, 2, 2
: 14 : 1, 3, 1, 5, 9, 3
Columns k=0-10 give:
A239241,
A239871(n+1),
A240138,
A240139,
A240140,
A240141,
A240142,
A240143,
A240144,
A240145,
A240146.
-
b:= proc(n, i) option remember; `if`(n>i*(i+1)/2, 0, `if`(n=0, 1,
expand(b(n, i-1)+`if`(i>n, 0, b(n-i, i-1)*x^(2*irem(i, 2)-1)))))
end:
T:= n-> (p-> seq(coeff(p, x, i), i=ldegree(p)..degree(p)))(b(n$2)):
seq(T(n), n=0..20);
-
b[n_, i_] := b[n, i] = If[n>i*(i+1)/2, 0, If[n == 0, 1, Expand[b[n, i-1] + If[i>n, 0, b[n-i, i-1]*x^(2*Mod[i, 2]-1)]]]]; T[n_] := Function[{p}, Table[ Coefficient[p, x, i], {i, Exponent[p, x, Min], Exponent[p, x]}]][b[n, n]]; Table[ T[n], {n, 0, 20}] // Flatten (* Jean-François Alcover, Feb 11 2015, after Alois P. Heinz *)
-
N=20; q='q+O('q^N);
e(n) = if(n%2!=0, u, 1/u);
gf = prod(n=1,N, 1 + e(n)*q^n );
V = Vec( gf );
{ for (j=1, #V, \\ print triangle, including leading zeros
for (i=0, N-j, print1(" ")); \\ padding
for (i=-j+1, j-1, print1(polcoeff(V[j], i, u),", "));
print();
); }
/* Joerg Arndt, Apr 01 2014 */
A350942
Number of odd parts minus number of even conjugate parts of the integer partition with Heinz number n.
Original entry on oeis.org
0, 1, 0, 1, 1, 0, 0, 3, -2, 1, 1, 2, 0, 0, -1, 3, 1, 0, 0, 3, -2, 1, 1, 2, -1, 0, 0, 2, 0, 1, 1, 5, -1, 1, -2, 0, 0, 0, -2, 3, 1, 0, 0, 3, 1, 1, 1, 4, -4, 1, -1, 2, 0, 0, -1, 2, -2, 0, 1, 1, 0, 1, 0, 5, -2, 1, 1, 3, -1, 0, 0, 2, 1, 0, 1, 2, -3, 0, 0, 5, -2, 1
Offset: 1
First positions n such that a(n) = 6, 5, 4, 3, 2, 1, 0, -1, -2, -3, -4, -5, -6, together with their prime indices, are:
192: (2,1,1,1,1,1,1)
32: (1,1,1,1,1)
48: (2,1,1,1,1)
8: (1,1,1)
12: (2,1,1)
2: (1)
1: ()
15: (3,2)
9: (2,2)
77: (5,4)
49: (4,4)
221: (7,6)
169: (6,6)
A122111 represents conjugation using Heinz numbers.
A316524 = alternating sum of prime indices.
The following rank partitions:
A325698: # of even parts = # of odd parts.
A349157: # of even parts = # of odd conjugate parts, counted by
A277579.
A350943: # of even conjugate parts = # of odd parts, counted by
A277579.
A350944: # of odd parts = # of odd conjugate parts, counted by
A277103.
A350945: # of even parts = # of even conjugate parts, counted by
A350948.
Cf.
A026424,
A028260,
A130780,
A171966,
A239241,
A241638,
A325700,
A350947,
A350949,
A350950,
A350951.
-
primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
conj[y_]:=If[Length[y]==0,y,Table[Length[Select[y,#>=k&]],{k,1,Max[y]}]];
Table[Count[primeMS[n],?OddQ]-Count[conj[primeMS[n]],?EvenQ],{n,100}]
A350947
Heinz numbers of integer partitions with the same number of even parts, odd parts, even conjugate parts, and odd conjugate parts.
Original entry on oeis.org
1, 6, 84, 210, 490, 525, 2184, 2340, 5460, 9464, 12012, 12740, 12870, 13650, 14625, 19152, 22308, 30030, 34125, 43940, 45144, 55770, 59150, 66066, 70070, 70785, 75075, 79625, 82992, 88920
Offset: 1
The terms together with their prime indices begin:
1: ()
6: (2,1)
84: (4,2,1,1)
210: (4,3,2,1)
490: (4,4,3,1)
525: (4,3,3,2)
2184: (6,4,2,1,1,1)
2340: (6,3,2,2,1,1)
5460: (6,4,3,2,1,1)
9464: (6,6,4,1,1,1)
12012: (6,5,4,2,1,1)
12740: (6,4,4,3,1,1)
12870: (6,5,3,2,2,1)
13650: (6,4,3,3,2,1)
14625: (6,3,3,3,2,2)
19152: (8,4,2,2,1,1,1,1)
For example, the partition (6,6,4,1,1,1) has conjugate (6,3,3,3,2,2), and all four statistics are equal to 3, so 9464 is in the sequence.
These partitions are counted by
A351978.
There are four individual statistics:
There are six possible pairings of statistics:
-
A349157: # of even parts = # of odd conjugate parts, counted by
A277579.
-
A350848: # of even conj parts = # of odd conj parts, counted by
A045931.
-
A350943: # of even conjugate parts = # of odd parts, counted by
A277579.
-
A350944: # of odd parts = # of odd conjugate parts, counted by
A277103.
-
A350945: # of even parts = # of even conjugate parts, counted by
A350948.
There are three possible double-pairings of statistics:
A122111 represents partition conjugation using Heinz numbers.
A195017 = # of even parts - # of odd parts.
A316524 = alternating sum of prime indices.
Cf.
A026424,
A028260,
A098123,
A239241,
A241638,
A325700,
A350849,
A350941,
A350942,
A350950,
A350951.
-
primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
conj[y_]:=If[Length[y]==0,y,Table[Length[Select[y,#>=k&]],{k,1,Max[y]}]];
Select[Range[1000],Count[primeMS[#],?EvenQ]==Count[primeMS[#],?OddQ]==Count[conj[primeMS[#]],?EvenQ]==Count[conj[primeMS[#]],?OddQ]&]
A350949
Heinz numbers of integer partitions with as many even parts as even conjugate parts and as many odd parts as odd conjugate parts.
Original entry on oeis.org
1, 2, 6, 9, 20, 30, 56, 75, 84, 125, 176, 210, 264, 294, 315, 350, 416, 441, 490, 525, 624, 660, 735, 924, 990, 1088, 1100, 1386, 1540, 1560, 1632, 1650, 1715, 2184, 2310, 2340, 2401, 2432, 2600, 3267, 3276, 3388, 3640, 3648, 3900, 4080, 4125, 5082, 5324, 5390
Offset: 1
The terms together with their prime indices begin:
1: ()
2: (1)
6: (2,1)
9: (2,2)
20: (3,1,1)
30: (3,2,1)
56: (4,1,1,1)
75: (3,3,2)
84: (4,2,1,1)
125: (3,3,3)
176: (5,1,1,1,1)
210: (4,3,2,1)
264: (5,2,1,1,1)
294: (4,4,2,1)
315: (4,3,2,2)
350: (4,3,3,1)
416: (6,1,1,1,1,1)
These partitions are counted by
A351976.
There are four other possible pairings of statistics:
There are two other possible double-pairings of statistics:
A122111 represents partition conjugation using Heinz numbers.
A195017 = # of even parts - # of odd parts.
A316524 = alternating sum of prime indices.
Cf.
A026424,
A028260,
A098123,
A130780,
A171966,
A241638,
A325700,
A350849,
A350941,
A350942,
A350950,
A350951.
-
primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
conj[y_]:=If[Length[y]==0,y,Table[Length[Select[y,#>=k&]],{k,1,Max[y]}]];
Select[Range[1000],Count[primeMS[#],?OddQ]==Count[conj[primeMS[#]],?OddQ]&&Count[primeMS[#],?EvenQ]==Count[conj[primeMS[#]],?EvenQ]&]
A098123
Number of compositions of n with equal number of even and odd parts.
Original entry on oeis.org
1, 0, 0, 2, 0, 4, 6, 6, 24, 28, 60, 130, 190, 432, 770, 1386, 2856, 5056, 9828, 18918, 34908, 68132, 128502, 244090, 470646, 890628, 1709136, 3271866, 6238986, 11986288, 22925630, 43932906, 84349336, 161625288, 310404768, 596009494
Offset: 0
From _Gus Wiseman_, Jun 26 2022: (Start)
The a(0) = 1 through a(7) = 6 compositions (empty columns indicated by dots):
() . . (12) . (14) (1122) (16)
(21) (23) (1212) (25)
(32) (1221) (34)
(41) (2112) (43)
(2121) (52)
(2211) (61)
(End)
These compositions are ranked by
A355321.
A026010
a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is a nonnegative integer and |s(i) - s(i-1)| = 1 for i = 1,2,...,n and s(0) = 2. Also a(n) = sum of numbers in row n+1 of array T defined in A026009.
Original entry on oeis.org
1, 2, 4, 7, 14, 25, 50, 91, 182, 336, 672, 1254, 2508, 4719, 9438, 17875, 35750, 68068, 136136, 260338, 520676, 999362, 1998724, 3848222, 7696444, 14858000, 29716000, 57500460, 115000920, 222981435, 445962870, 866262915, 1732525830, 3370764540
Offset: 0
The a(3) = 7 compositions of 5 in which the even parts appear as often at even positions as at odd positions are (5), (311), (131), (113), (221), (122), (11111). Missing are (41), (14), (32), (23), (212), (2111), (1211), (1121), (1112). - _Gus Wiseman_, Mar 17 2018
Cf.
A000712,
A001405,
A005774,
A045931,
A063886,
A097613,
A130780,
A171966,
A239241,
A299926,
A300061,
A300787,
A300788,
A300789.
-
[(&+[Binomial(Floor((n+k)/2), Floor(k/2)): k in [0..n]]): n in [0..40]]; // G. C. Greubel, Nov 08 2018
-
Array[Sum[Binomial[Floor[(# + k)/2], Floor[k/2]], {k, 0, #}] &, 34, 0] (* Michael De Vlieger, May 16 2018 *)
Table[2^(-1 + n)*(((2 + 3*#)*Gamma[(1 + #)/2])/(Sqrt[Pi]*Gamma[2 + #/2]) &[n + Mod[n, 2]]), {n,0,40}] (* Peter Pein, Nov 08 2018 *)
Table[(1/2)^((5 - (-1)^n)/2)*(6*n + 7 - 3*(-1)^n)*CatalanNumber[(2*n + 1 - (-1)^n)/4], {n, 0, 40}] (* G. C. Greubel, Nov 08 2018 *)
-
vector(40, n, n--; sum(k=0,n, binomial(floor((n+k)/2), floor(k/2)))) \\ G. C. Greubel, Nov 08 2018
A350849
Number of odd conjugate parts minus number of even parts in the integer partition with Heinz number n.
Original entry on oeis.org
0, 1, 1, 0, 3, 0, 3, 1, -2, 2, 5, 1, 5, 2, 0, 0, 7, -1, 7, 3, 0, 4, 9, 0, 0, 4, -1, 3, 9, 1, 11, 1, 2, 6, 0, -2, 11, 6, 2, 2, 13, 1, 13, 5, 1, 8, 15, 1, -2, 1, 4, 5, 15, -2, 2, 2, 4, 8, 17, 0, 17, 10, 1, 0, 2, 3, 19, 7, 6, 1, 19, -1, 21, 10, 1, 7, 0, 3, 21, 3
Offset: 1
First positions n such that a(n) = 4, 3, 2, 1, 0, -1, -2, -3, -4, together with their prime indices, are:
22: (5,1)
5: (3)
10: (3,1)
2: (1)
1: ()
18: (2,2,1)
9: (2,2)
162: (2,2,2,2,1)
81: (2,2,2,2)
Counting even conjugate parts instead of even parts gives
A350941.
The following rank partitions:
A325698: # of even parts = # of odd parts.
A349157: # of even parts = # of odd conjugate parts, counted by
A277579.
A350943: # of even conjugate parts = # of odd parts, counted by
A277579.
A350944: # of odd parts = # of odd conjugate parts, counted by
A277103.
A350945: # of even parts = # of even conjugate parts, counted by
A350948.
A122111 represents conjugation using Heinz numbers.
A316524 = alternating sum of prime indices.
Cf.
A026424,
A028260,
A130780,
A171966,
A239241,
A241638,
A325700,
A350947,
A350949,
A350950,
A350951.
-
primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
conj[y_]:=If[Length[y]==0,y,Table[Length[Select[y,#>=k&]],{k,1,Max[y]}]];
Table[Count[conj[primeMS[n]],?OddQ]-Count[primeMS[n],?EvenQ],{n,100}]
A350946
Heinz numbers of integer partitions with as many even parts as odd parts and as many even conjugate parts as odd conjugate parts.
Original entry on oeis.org
1, 6, 65, 84, 210, 216, 319, 490, 525, 532, 731, 1254, 1403, 1924, 2184, 2340, 2449, 2470, 3024, 3135, 3325, 3774, 4028, 4141, 4522, 5311, 5460, 7030, 7314, 7315, 7560, 7776, 7942, 8201, 8236, 9048, 9435, 9464, 10659, 10921, 11484, 11914, 12012, 12025, 12740
Offset: 1
The terms together with their prime indices begin:
1: ()
6: (2,1)
65: (6,3)
84: (4,2,1,1)
210: (4,3,2,1)
216: (2,2,2,1,1,1)
319: (10,5)
490: (4,4,3,1)
525: (4,3,3,2)
532: (8,4,1,1)
731: (14,7)
1254: (8,5,2,1)
1403: (18,9)
1924: (12,6,1,1)
2184: (6,4,2,1,1,1)
2340: (6,3,2,2,1,1)
2449: (22,11)
2470: (8,6,3,1)
For example, the prime indices of 532 are (8,4,1,1), even/odd counts 2/2, and the prime indices of the conjugate 3024 are (4,2,2,2,1,1,1,1), with even/odd counts 4/4; so 532 belongs to the sequence.
For the first condition alone:
- ordered version (compositions)
A098123
There are four statistics:
There are four other possible pairings of statistics:
-
A349157: # of even parts = # of odd conjugate parts, counted by
A277579.
-
A350943: # of even conj parts = # of odd parts, strict counted by
A352130.
-
A350944: # of odd parts = # of odd conjugate parts, counted by
A277103.
-
A350945: # of even parts = # of even conjugate parts, counted by
A350948.
There are two other possible double-pairings of statistics:
A122111 represents partition conjugation using Heinz numbers.
A195017 = # of even parts - # of odd parts.
A316524 = alternating sum of prime indices.
-
primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
conj[y_]:=If[Length[y]==0,y,Table[Length[Select[y,#>=k&]],{k,1,Max[y]}]];
Select[Range[1000],#==1||Mean[Mod[primeMS[#],2]]== Mean[Mod[conj[primeMS[#]],2]]==1/2&]
A350950
Number of even parts minus number of even conjugate parts in the integer partition with Heinz number n.
Original entry on oeis.org
0, 0, 1, -1, 0, 0, 1, 0, 0, -1, 0, 1, 1, 0, -1, -1, 0, 1, 1, 0, 0, 1, 0, 0, -3, 0, 3, 1, 1, 0, 0, 0, -1, -1, -2, 0, 1, 0, 0, -1, 0, 1, 1, 0, 2, -1, 0, 1, -2, -2, -1, 1, 1, 2, -3, 0, 0, 0, 0, -1, 1, -1, 3, -1, -2, 0, 0, 0, -1, -1, 1, 1, 0, 0, 0, 1, -3, 1, 1, 0
Offset: 1
The prime indices of 78 are (6,2,1), with conjugate (3,2,1,1,1,1), so a(78) = 2 - 1 = 1.
The version comparing even with odd parts is
A195017.
The version comparing even with odd conjugate parts is
A350849.
The version comparing even conjugate with odd conjugate parts is
A350941.
The version comparing odd with even conjugate parts is
A350942.
The version comparing odd with odd conjugate parts is
A350951.
There are four individual statistics:
There are five other possible pairings of statistics:
-
A349157: # of even parts = # of odd conjugate parts, counted by
A277579.
-
A350848: # of even conj parts = # of odd conj parts, counted by
A045931.
-
A350943: # of even conjugate parts = # of odd parts, counted by
A277579.
-
A350944: # of odd parts = # of odd conjugate parts, counted by
A277103.
There are three possible double-pairings of statistics:
A116482 counts partitions by number of even parts.
A122111 represents partition conjugation using Heinz numbers.
A316524 gives the alternating sum of prime indices.
-
primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
conj[y_]:=If[Length[y]==0,y,Table[Length[Select[y,#>=k&]],{k,1,Max[y]}]];
Table[Count[primeMS[n],?EvenQ]-Count[conj[primeMS[n]],?EvenQ],{n,100}]
Comments