A015723
Number of parts in all partitions of n into distinct parts.
Original entry on oeis.org
1, 1, 3, 3, 5, 8, 10, 13, 18, 25, 30, 40, 49, 63, 80, 98, 119, 149, 179, 218, 266, 318, 380, 455, 541, 640, 760, 895, 1050, 1234, 1442, 1679, 1960, 2272, 2635, 3052, 3520, 4054, 4669, 5359, 6142, 7035, 8037, 9170, 10460, 11896, 13517, 15349, 17394, 19691
Offset: 1
The strict integer partitions of 6 are {(6), (5,1), (4,2), (3,2,1)} with a total of 1 + 2 + 2 + 3 = 8 parts, so a(6) = 8. - _Gus Wiseman_, May 09 2019
- Alois P. Heinz, Table of n, a(n) for n = 1..10000 (first 1000 terms from T. D. Noe)
- Martin Klazar, What is an answer? — remarks, results and problems on PIO formulas in combinatorial enumeration, part I, arXiv:1808.08449 [math.CO], 2018.
- Arnold Knopfmacher, and Neville Robbins, Identities for the total number of parts in partitions of integers, Util. Math. 67 (2005), 9-18.
- Mircea Merca, Combinatorial interpretations of a recent convolution for the number of divisors of a positive integer, Journal of Number Theory, Volume 160, March 2016, Pages 60-75. See s(n).
- Eric Weisstein's World of Mathematics, q-Polygamma Function, q-Pochhammer Symbol.
-
b:= proc(n, i) option remember; `if`(n=0, [1, 0], `if`(i<1, [0, 0],
add((l->[l[1], l[2]+l[1]*j])(b(n-i*j, i-1)), j=0..min(n/i, 1))))
end:
a:= n-> b(n, n)[2]:
seq(a(n), n=1..50); # Alois P. Heinz, Feb 27 2013
-
nn=50; Rest[CoefficientList[Series[D[Product[1+y x^i,{i,1,nn}],y]/.y->1,{x,0,nn}],x]] (* Geoffrey Critzer, Oct 29 2012; fixed by Vaclav Kotesovec, Apr 16 2016 *)
q[n_, k_] := q[n, k] = If[nVaclav Kotesovec, Apr 16 2016 *)
Table[Length[Join@@Select[IntegerPartitions[n],UnsameQ@@#&]],{n,1,50}] (* Gus Wiseman, May 09 2019 *)
b[n_, i_] := b[n, i] = If[n == 0, {1, 0}, If[i<1, {0, 0},
Sum[{#[[1]], #[[2]] + #[[1]]*j}&@ b[n-i*j, i-1], {j, 0, Min[n/i, 1]}]]];
a[n_] := b[n, n][[2]];
Array[a, 50] (* Jean-François Alcover, May 21 2021, after Alois P. Heinz *)
-
N=66; q='q+O('q^N); gf=sum(n=0,N, n*q^(n*(n+1)/2) / prod(k=1,n, 1-q^k ) );
Vec(gf) /* Joerg Arndt, Oct 20 2012 */
A147655
a(n) is the coefficient of x^n in the polynomial given by Product_{k>=1} (1 + prime(k)*x^k).
Original entry on oeis.org
1, 2, 3, 11, 17, 40, 86, 153, 283, 547, 1069, 1737, 3238, 5340, 9574, 17251, 27897, 45845, 78601, 126725, 207153, 353435, 550422, 881454, 1393870, 2239938, 3473133, 5546789, 8762663, 13341967, 20676253, 31774563, 48248485, 74174759, 111904363, 170184798
Offset: 0
Form a product from the primes: (1 + 2*x) * (1 + 3*x^2) * (1 + 5*x^3) * ...* (1 + prime(n)*x^n) * ... Multiplying out gives 1 + 2*x + 3*x^2 + 11*x^3 + ..., so the sequence begins 1, 2, 3, 11, ....
From _Petros Hadjicostas_, Apr 10 2020: (Start)
Let f(m) = prime(m). Using the strict partitions of n (see A000009), we get:
a(1) = f(1) = 2,
a(2) = f(2) = 3,
a(3) = f(3) + f(1)*f(2) = 5 + 2*3 = 11,
a(4) = f(4) + f(1)*f(3) = 7 + 2*5 = 17,
a(5) = f(5) + f(1)*f(4) + f(2)*f(3) = 11 + 2*7 + 3*5 = 40,
a(6) = f(6) + f(1)*f(5) + f(2)*f(4) + f(1)*f(2)*f(3) = 13 + 2*11 + 3*7 + 2*3*5 = 86,
a(7) = f(7) + f(1)*f(6) + f(2)*f(5) + f(3)*f(4) + f(1)*f(2)*f(4) = 17 + 2*13 + 3*11 + 5*7 + 2*3*7 = 153. (End)
Cf.
A000009,
A005117,
A015723,
A022629,
A056239,
A066189,
A112798,
A145519,
A147541,
A325504,
A325506,
A325537.
-
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
b(n, i-1) +`if`(i>n, 0, b(n-i, i-1)*ithprime(i))))
end:
a:= n-> b(n$2):
seq(a(n), n=0..50); # Alois P. Heinz, Sep 05 2014
-
nn=40;Take[Rest[CoefficientList[Expand[Times@@Table[1+Prime[n]x^n,{n,nn}]],x]],nn] (* Harvey P. Dale, Jul 01 2012 *)
A246688
Triangle in which n-th row lists lexicographically ordered increasing lists of parts of all partitions of n into distinct parts.
Original entry on oeis.org
1, 2, 1, 2, 3, 1, 3, 4, 1, 4, 2, 3, 5, 1, 2, 3, 1, 5, 2, 4, 6, 1, 2, 4, 1, 6, 2, 5, 3, 4, 7, 1, 2, 5, 1, 3, 4, 1, 7, 2, 6, 3, 5, 8, 1, 2, 6, 1, 3, 5, 1, 8, 2, 3, 4, 2, 7, 3, 6, 4, 5, 9, 1, 2, 3, 4, 1, 2, 7, 1, 3, 6, 1, 4, 5, 1, 9, 2, 3, 5, 2, 8, 3, 7, 4, 6, 10
Offset: 1
Triangle begins:
[1];
[2];
[1,2], [3];
[1,3], [4];
[1,4], [2,3], [5];
[1,2,3], [1,5], [2,4], [6];
[1,2,4], [1,6], [2,5], [3,4], [7];
[1,2,5], [1,3,4], [1,7], [2,6], [3,5], [8];
[1,2,6], [1,3,5], [1,8], [2,3,4], [2,7], [3,6], [4,5], [9];
[1,2,3,4], [1,2,7], [1,3,6], [1,4,5], [1,9], [2,3,5], [2,8], [3,7], [4,6], [10];
-
b:= proc(n, i) b(n, i):= `if`(n=0, [[]], `if`(i>n, [],
[map(x->[i, x[]], b(n-i, i+1))[], b(n, i+1)[]]))
end:
T:= n-> map(x-> x[], b(n, 1))[]:
seq(T(n), n=1..12);
-
T[n_] := Module[{ip, lg}, ip = Reverse /@ Select[ IntegerPartitions[n], # == DeleteDuplicates[#]&]; lg = Length /@ ip // Max; SortBy[PadRight[#, lg]&][ip]];
Table[T[n], {n, 1, 12}] // Flatten (* Jean-François Alcover, Oct 21 2022 *)
A325504
Product of products of parts over all strict integer partitions of n.
Original entry on oeis.org
1, 1, 2, 6, 12, 120, 1440, 40320, 1209600, 1567641600, 2633637888000, 13905608048640000, 5046067048690483200000, 5289893008483207348224000000, 1266933607446134946465526579200000000, 99304891373531545064656621572980736000000000000
Offset: 0
The strict partitions of 5 are {(5), (4,1), (3,2)} with product a(5) = 5*4*1*3*2 = 120.
The sequence of terms together with their prime indices begins:
1: {}
1: {}
2: {1}
6: {1,2}
12: {1,1,2}
120: {1,1,1,2,3}
1440: {1,1,1,1,1,2,2,3}
40320: {1,1,1,1,1,1,1,2,2,3,4}
1209600: {1,1,1,1,1,1,1,1,2,2,2,3,3,4}
1567641600: {1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,3,3,4}
2633637888000: {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,3,3,3,4,4}
Cf.
A000009,
A006128,
A007870 (non-strict version),
A015723,
A022629 (sum of products of parts),
A066186,
A066189,
A066633,
A246867,
A325505,
A325506,
A325512,
A325513,
A325515.
-
a:= n-> mul(i, i=map(x-> x[], select(x->
nops(x)=nops({x[]}), combinat[partition](n)))):
seq(a(n), n=0..15); # Alois P. Heinz, Aug 03 2021
# second Maple program:
b:= proc(n, i) option remember; `if`(n=0, [1$2], `if`(i<1, [0, 1], ((f, g)->
[f[1]+g[1], f[2]*g[2]*i^g[1]])(b(n, i-1), b(n-i, min(n-i, i-1)))))
end:
a:= n-> b(n$2)[2]:
seq(a(n), n=0..15); # Alois P. Heinz, Aug 03 2021
-
Table[Times@@Join@@Select[IntegerPartitions[n],UnsameQ@@#&],{n,0,10}]
A344086
Flattened tetrangle of strict integer partitions sorted first by sum, then lexicographically.
Original entry on oeis.org
1, 2, 2, 1, 3, 3, 1, 4, 3, 2, 4, 1, 5, 3, 2, 1, 4, 2, 5, 1, 6, 4, 2, 1, 4, 3, 5, 2, 6, 1, 7, 4, 3, 1, 5, 2, 1, 5, 3, 6, 2, 7, 1, 8, 4, 3, 2, 5, 3, 1, 5, 4, 6, 2, 1, 6, 3, 7, 2, 8, 1, 9, 4, 3, 2, 1, 5, 3, 2, 5, 4, 1, 6, 3, 1, 6, 4, 7, 2, 1, 7, 3, 8, 2, 9, 1, 10
Offset: 0
Tetrangle begins:
0: ()
1: (1)
2: (2)
3: (21)(3)
4: (31)(4)
5: (32)(41)(5)
6: (321)(42)(51)(6)
7: (421)(43)(52)(61)(7)
8: (431)(521)(53)(62)(71)(8)
9: (432)(531)(54)(621)(63)(72)(81)(9)
Positions of first appearances are
A015724.
Taking revlex instead of lex gives
A118457.
The not necessarily strict version is
A193073.
The version for reversed partitions is
A246688.
The Heinz numbers of these partitions grouped by sum are
A246867.
The ordered generalization is
A339351.
Taking colex instead of lex gives
A344087.
A026793 gives reversed strict partitions in A-S order (sum/length/lex).
A319247 sorts reversed strict partitions by Heinz number.
A329631 sorts strict partitions by Heinz number.
A344090 gives strict partitions in A-S order (sum/length/lex).
Partition/composition orderings:
A026791,
A026792,
A036036,
A036037,
A048793,
A066099,
A080577,
A112798,
A124734,
A162247,
A211992,
A228100,
A228351,
A228531,
A272020,
A299755,
A296774,
A304038,
A334301,
A334302,
A334439,
A334442,
A335122,
A344085,
A344086,
A344088,
A344089.
Partition/composition applications:
A001793,
A005183,
A036043,
A049085,
A070939,
A115623,
A124736,
A129129,
A185974,
A238966,
A294648,
A333483,
A333484,
A333485,
A333486,
A334433,
A334434,
A334435,
A334436,
A334437,
A334438,
A334440,
A334441,
A335123,
A335124,
A339195.
-
lexsort[f_,c_]:=OrderedQ[PadRight[{f,c}]];
Table[Sort[Select[IntegerPartitions[n],UnsameQ@@#&],lexsort],{n,0,8}]
A325506
Product of Heinz numbers over all strict integer partitions of n.
Original entry on oeis.org
1, 2, 3, 30, 70, 2310, 180180, 21441420, 6401795400, 200984366583000, 41615822944675980000, 10515527757483671302380000, 4919824049783476260137727416400000, 5158181210492841550866520676965246284000000, 29776760895364738730693151196801613158042403043600000000
Offset: 0
The strict integer partitions of 6 are {(6), (5,1), (4,2), (3,2,1)}, with Heinz numbers {13,22,21,30}, with product 13*22*21*30 = 180180, so a(6) = 180180.
The sequence of terms together with their prime indices begins:
1: {}
2: {1}
3: {2}
30: {1,2,3}
70: {1,3,4}
2310: {1,2,3,4,5}
180180: {1,1,2,2,3,4,5,6}
21441420: {1,1,2,2,3,4,4,5,6,7}
6401795400: {1,1,1,2,2,3,3,4,5,5,6,7,8}
200984366583000: {1,1,1,2,2,2,3,3,3,4,4,5,5,6,6,7,8,9}
41615822944675980000: {1,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,5,5,6,6,7,7,8,9,10}
Cf.
A003963,
A006128,
A015723,
A022629,
A056239,
A112798,
A147655,
A215366,
A246867,
A325501,
A325504,
A325505,
A325512,
A325513.
-
Table[Times@@Prime/@(Join@@Select[IntegerPartitions[n],UnsameQ@@#&]),{n,0,15}]
A344089
Flattened tetrangle of reversed strict integer partitions, sorted first by length and then colexicographically.
Original entry on oeis.org
1, 2, 3, 1, 2, 4, 1, 3, 5, 2, 3, 1, 4, 6, 2, 4, 1, 5, 1, 2, 3, 7, 3, 4, 2, 5, 1, 6, 1, 2, 4, 8, 3, 5, 2, 6, 1, 7, 1, 3, 4, 1, 2, 5, 9, 4, 5, 3, 6, 2, 7, 1, 8, 2, 3, 4, 1, 3, 5, 1, 2, 6, 10, 4, 6, 3, 7, 2, 8, 1, 9, 2, 3, 5, 1, 4, 5, 1, 3, 6, 1, 2, 7, 1, 2, 3, 4
Offset: 0
Tetrangle begins:
0: ()
1: (1)
2: (2)
3: (3)(12)
4: (4)(13)
5: (5)(23)(14)
6: (6)(24)(15)(123)
7: (7)(34)(25)(16)(124)
8: (8)(35)(26)(17)(134)(125)
9: (9)(45)(36)(27)(18)(234)(135)(126)
Positions of first appearances are
A015724 plus one.
Reversing all partitions gives
A344090.
A319247 sorts strict partitions by Heinz number.
A329631 sorts reversed strict partitions by Heinz number.
Partition/composition orderings:
A026791,
A026792,
A036036,
A036037,
A048793,
A066099,
A080577,
A112798,
A124734,
A162247,
A193073,
A211992,
A228100,
A228351,
A228531,
A246688,
A272020,
A299755,
A296774,
A304038,
A334301,
A334302,
A334439,
A334442,
A335122,
A339351,
A344085,
A344086,
A344087,
A344088,
A344089.
Partition/composition applications:
A001793,
A005183,
A036043,
A049085,
A070939,
A115623,
A124736,
A129129,
A185974,
A238966,
A246867,
A294648,
A333483,
A333484,
A333485,
A333486,
A334433,
A334434,
A334435,
A334436,
A334437,
A334438,
A334440,
A334441,
A335123,
A335124,
A339195.
-
Table[Reverse/@Sort[Select[IntegerPartitions[n],UnsameQ@@#&]],{n,0,30}]
A325505
Heinz number of the set of Heinz numbers of all strict integer partitions of n.
Original entry on oeis.org
2, 3, 5, 143, 493, 62651, 26718511, 22017033127, 44220524211551, 52289759420183033963, 546407750301194131199484983, 8362548333129019658779663581495109, 1828111016191440393570169991636207115709029581, 1059934964500839879758659437301868941873808925011368355891
Offset: 0
The strict integer partitions of 5 are {(5), (4,1), (3,2)}, with Heinz numbers {11,14,15}, with Heinz number prime(11)*prime(14)*prime(15) = 62651, so a(6) = 62651.
The sequence of terms together with their prime indices begins:
2: {1}
3: {2}
5: {3}
143: {5,6}
493: {7,10}
62651: {11,14,15}
26718511: {13,21,22,30}
22017033127: {17,26,33,35,42}
44220524211551: {19,34,39,55,66,70}
52289759420183033963: {23,38,51,65,77,78,105,110}
546407750301194131199484983: {29,46,57,85,91,102,130,154,165,210}
Cf.
A001222,
A003963,
A015723,
A056239,
A066189,
A112798,
A145519,
A147655,
A215366,
A246867,
A325500 (non-strict version),
A325504,
A325506,
A325512,
A325513.
A015716
Triangle read by rows: T(n,k) is the number of partitions of n into distinct parts, one of which is k (1<=k<=n).
Original entry on oeis.org
1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 2, 1, 2, 1, 1, 1, 3, 2, 2, 1, 2, 1, 1, 1, 3, 3, 3, 2, 2, 2, 1, 1, 1, 5, 4, 4, 3, 2, 2, 2, 1, 1, 1, 5, 5, 4, 3, 3, 3, 2, 2, 1, 1, 1, 7, 6, 5, 5, 4, 3, 3, 2, 2, 1, 1, 1, 8, 7, 6, 6, 4, 4, 4, 3, 2, 2, 1, 1
Offset: 1
T(8,3)=2 because we have [5,3] and [4,3,1].
Triangle begins:
n/k 1 2 3 4 5 6 7 8 9 10
01: 1
02: 0 1
03: 1 1 1
04: 1 0 1 1
05: 1 1 1 1 1
06: 2 2 1 1 1 1
07: 2 2 1 2 1 1 1
08: 3 2 2 1 2 1 1 1
09: 3 3 3 2 2 2 1 1 1
10: 5 4 4 3 2 2 2 1 1 1
...
The strict integer partitions of 6 are {(6), (5,1), (4,2), (3,2,1)}, with multiset union {1,1,2,2,3,4,5,6}, with multiplicities (2,2,1,1,1,1), which is row n = 6. - _Gus Wiseman_, May 07 2019
-
g:=product(1+x^j,j=1..50)*sum(t^i*x^i/(1+x^i),i=1..50): gser:=simplify(series(g,x=0,18)): for n from 1 to 14 do P[n]:=sort(coeff(gser,x^n)) od: for n from 1 to 14 do seq(coeff(P[n],t,j),j=1..n) od; # yields sequence in triangular form - Emeric Deutsch, Mar 29 2006
seq(seq(coeff(x^k*(product(1+x^j, j=1..n))/(1+x^k), x, n), k=1..n), n=1..13); # Mircea Merca, Feb 28 2014
-
z = 15; d[n_] := d[n] = Select[IntegerPartitions[n], DeleteDuplicates[#] == # &]; p[n_, k_] := p[n, k] = d[n][[k]]; s[n_] := s[n] = Flatten[Table[p[n, k], {k, 1, PartitionsQ[n]}]]; t[n_, k_] := Count[s[n], k]; u = Table[t[n, k], {n, 1, z}, {k, 1, n}]; TableForm[u] (* A015716 as a triangle *)
v = Flatten[u] (* A015716 as a sequence *)
(* Clark Kimberling, Mar 14 2014 *)
A344087
Flattened tetrangle of strict integer partitions sorted first by sum, then colexicographically.
Original entry on oeis.org
1, 2, 2, 1, 3, 3, 1, 4, 4, 1, 3, 2, 5, 3, 2, 1, 5, 1, 4, 2, 6, 4, 2, 1, 6, 1, 5, 2, 4, 3, 7, 5, 2, 1, 4, 3, 1, 7, 1, 6, 2, 5, 3, 8, 6, 2, 1, 5, 3, 1, 8, 1, 4, 3, 2, 7, 2, 6, 3, 5, 4, 9, 4, 3, 2, 1, 7, 2, 1, 6, 3, 1, 5, 4, 1, 9, 1, 5, 3, 2, 8, 2, 7, 3, 6, 4, 10
Offset: 0
Tetrangle begins:
0: ()
1: (1)
2: (2)
3: (21)(3)
4: (31)(4)
5: (41)(32)(5)
6: (321)(51)(42)(6)
7: (421)(61)(52)(43)(7)
8: (521)(431)(71)(62)(53)(8)
9: (621)(531)(81)(432)(72)(63)(54)(9)
Positions of first appearances are
A015724.
Taking revlex instead of colex gives
A118457.
The not necessarily strict version is
A211992.
Taking lex instead of colex gives
A344086.
A026793 gives reversed strict partitions in A-S order (sum/length/lex).
A319247 sorts strict partitions by Heinz number.
A329631 sorts reversed strict partitions by Heinz number.
A344090 gives strict partitions in A-S order (sum/length/lex).
Partition/composition orderings:
A026791,
A026792,
A036036,
A036037,
A048793,
A066099,
A080576,
A080577,
A112798,
A124734,
A162247,
A193073,
A211992,
A228100,
A228351,
A228531,
A246688,
A272020,
A299755,
A296774,
A304038,
A319247,
A334301,
A334302,
A334439,
A334442,
A335122,
A339351,
A344085,
A344086,
A344088,
A344089,
A344091.
Partition/composition applications:
A001793,
A005183,
A036043,
A049085,
A070939,
A115623,
A124736,
A129129,
A185974,
A238966,
A246867,
A294648,
A333483,
A333484,
A333485,
A333486,
A334433,
A334434,
A334435,
A334436,
A334437,
A334438,
A334440,
A334441,
A335123,
A335124,
A339195.
-
colex[f_,c_]:=OrderedQ[PadRight[{Reverse[f],Reverse[c]}]];
Table[Sort[Select[IntegerPartitions[n],UnsameQ@@#&],colex],{n,0,10}]
Showing 1-10 of 28 results.
Comments