A078374
Number of partitions of n into distinct and relatively prime parts.
Original entry on oeis.org
1, 0, 1, 1, 2, 2, 4, 4, 6, 7, 11, 10, 17, 17, 23, 26, 37, 36, 53, 53, 70, 77, 103, 103, 139, 147, 184, 199, 255, 260, 339, 358, 435, 474, 578, 611, 759, 810, 963, 1045, 1259, 1331, 1609, 1726, 2015, 2200, 2589, 2762, 3259, 3509, 4058, 4416, 5119, 5488, 6364, 6882
Offset: 1
From _Gus Wiseman_, Oct 18 2020: (Start)
The a(1) = 1 through a(13) = 17 partitions (empty column indicated by dot, A = 10, B = 11, C = 12):
1 . 21 31 32 51 43 53 54 73 65 75 76
41 321 52 71 72 91 74 B1 85
61 431 81 532 83 543 94
421 521 432 541 92 651 A3
531 631 A1 732 B2
621 721 542 741 C1
4321 632 831 643
641 921 652
731 5421 742
821 6321 751
5321 832
841
931
A21
5431
6421
7321
(End)
A000837 is the not necessarily strict version.
A302796 gives the Heinz numbers of these partitions.
A305713 is the pairwise coprime instead of relatively prime version.
A000740 counts relatively prime compositions.
Cf.
A007359,
A101268,
A289508,
A289509,
A291166,
A298748,
A337451,
A337485,
A337451,
A337561,
A337563.
-
Table[Length[Select[IntegerPartitions[n],UnsameQ@@#&&GCD@@#==1&]],{n,15}] (* Gus Wiseman, Oct 18 2020 *)
A101268
Number of compositions of n into pairwise relatively prime parts.
Original entry on oeis.org
1, 1, 2, 4, 7, 13, 22, 38, 63, 101, 160, 254, 403, 635, 984, 1492, 2225, 3281, 4814, 7044, 10271, 14889, 21416, 30586, 43401, 61205, 85748, 119296, 164835, 226423, 309664, 422302, 574827, 781237, 1060182, 1436368, 1942589, 2622079, 3531152, 4742316, 6348411
Offset: 0
From _Gus Wiseman_, Oct 18 2020: (Start)
The a(1) = 1 through a(5) = 13 compositions:
(1) (2) (3) (4) (5)
(11) (12) (13) (14)
(21) (31) (23)
(111) (112) (32)
(121) (41)
(211) (113)
(1111) (131)
(311)
(1112)
(1121)
(1211)
(2111)
(11111)
(End)
A337461 counts these compositions of length 3, with unordered version
A307719 and unordered strict version
A220377.
A337462 does not consider a singleton to be coprime unless it is (1), with strict version
A337561.
A337664 looks only at distinct parts, with non-constant version
A337665.
A000740 counts relatively prime compositions, with strict case
A332004.
A178472 counts compositions with a common factor.
-
Table[Length[Select[Join@@Permutations/@IntegerPartitions[n],Length[#]<=1||CoprimeQ@@#&]],{n,0,10}] (* Gus Wiseman, Oct 18 2020 *)
A327516
Number of integer partitions of n that are empty, (1), or have at least two parts and these parts are pairwise coprime.
Original entry on oeis.org
1, 1, 1, 2, 3, 5, 6, 9, 11, 14, 17, 22, 26, 32, 37, 42, 50, 59, 69, 80, 91, 101, 115, 133, 152, 170, 190, 210, 235, 265, 300, 334, 366, 398, 441, 484, 541, 597, 648, 703, 770, 848, 935, 1022, 1102, 1184, 1281, 1406, 1534, 1661, 1789, 1916, 2062, 2244, 2435
Offset: 0
The a(1) = 1 through a(8) = 11 partitions:
(1) (11) (21) (31) (32) (51) (43) (53)
(111) (211) (41) (321) (52) (71)
(1111) (311) (411) (61) (431)
(2111) (3111) (511) (521)
(11111) (21111) (3211) (611)
(111111) (4111) (5111)
(31111) (32111)
(211111) (41111)
(1111111) (311111)
(2111111)
(11111111)
A000837 is the relatively prime instead of pairwise coprime version.
A101268 is the ordered version (with singletons).
A307719 counts these partitions of length 3.
A018783 counts partitions with a common divisor.
A328673 counts pairwise non-coprime partitions.
-
Table[Length[Select[IntegerPartitions[n],#=={}||CoprimeQ@@#&]],{n,0,30}]
A220377
Number of partitions of n into three distinct and mutually relatively prime parts.
Original entry on oeis.org
1, 0, 2, 1, 3, 1, 6, 1, 7, 3, 7, 3, 14, 3, 15, 6, 14, 6, 25, 6, 22, 10, 25, 9, 42, 8, 34, 15, 37, 15, 53, 13, 48, 22, 53, 17, 78, 17, 65, 30, 63, 24, 99, 24, 88, 35, 84, 30, 126, 34, 103, 45, 103, 38, 166, 35, 124, 57, 128, 51, 184, 44, 150, 67, 172, 52, 218
Offset: 6
For n=10 we have three such partitions: 1+2+7, 1+4+5 and 2+3+5.
From _Gus Wiseman_, Oct 14 2020: (Start)
The a(6) = 1 through a(20) = 15 triples (empty column indicated by dot, A..H = 10..17):
321 . 431 531 532 731 543 751 743 753 754 971 765 B53 875
521 541 651 752 951 853 B51 873 B71 974
721 732 761 B31 871 D31 954 D51 A73
741 851 952 972 A91
831 941 B32 981 B54
921 A31 B41 A71 B72
B21 D21 B43 B81
B52 C71
B61 D43
C51 D52
D32 D61
D41 E51
E31 F41
F21 G31
H21
(End)
A101271 is the relative prime instead of pairwise coprime version.
A305713 counts these partitions of any length, with Heinz numbers
A302797.
A337461 is the non-strict ordered version.
A337605 is the pairwise non-coprime instead of pairwise coprime version.
A001399(n-6) counts strict 3-part partitions, with Heinz numbers
A007304.
A008284 counts partitions by sum and length, with strict case
A008289.
A318717 counts pairwise non-coprime strict partitions.
A326675 ranks pairwise coprime sets.
A327516 counts pairwise coprime partitions.
A337601 counts 3-part partitions whose distinct parts are pairwise coprime.
-
Table[Length@Select[ IntegerPartitions[ n, {3}], #[[1]] != #[[2]] != #[[3]] && GCD[#[[1]], #[[2]]] == 1 && GCD[#[[1]], #[[3]]] == 1 && GCD[#[[2]], #[[3]]] == 1 &], {n, 6, 100}]
Table[Count[IntegerPartitions[n,{3}],?(CoprimeQ@@#&&Length[ Union[#]] == 3&)],{n,6,100}] (* _Harvey P. Dale, May 22 2020 *)
-
a(n)=my(P=partitions(n));sum(i=1,#P,#P[i]==3&&P[i][1]Charles R Greathouse IV, Dec 14 2012
A307719
Number of partitions of n into 3 mutually coprime parts.
Original entry on oeis.org
0, 0, 0, 1, 1, 1, 2, 1, 3, 2, 4, 2, 7, 2, 8, 4, 8, 4, 15, 4, 16, 7, 15, 7, 26, 7, 23, 11, 26, 10, 43, 9, 35, 16, 38, 16, 54, 14, 49, 23, 54, 18, 79, 18, 66, 31, 64, 25, 100, 25, 89, 36, 85, 31, 127, 35, 104, 46, 104, 39, 167, 36, 125, 58, 129, 52, 185, 45
Offset: 0
There are 2 partitions of 9 into 3 mutually coprime parts: 7+1+1 = 5+3+1, so a(9) = 2.
There are 4 partitions of 10 into 3 mutually coprime parts: 8+1+1 = 7+2+1 = 5+4+1 = 5+3+2, so a(10) = 4.
There are 2 partitions of 11 into 3 mutually coprime parts: 9+1+1 = 7+3+1, so a(11) = 2.
There are 7 partitions of 12 into 3 mutually coprime parts: 10+1+1 = 9+2+1 = 8+3+1 = 7+4+1 = 6+5+1 = 7+3+2 = 5+4+3, so a(12) = 7.
A337599 is the pairwise non-coprime instead of pairwise coprime version.
A337601 only requires the distinct parts to be pairwise coprime.
-
N:= 200: # to get a(0)..a(N)
A:= Array(0..N):
for a from 1 to N/3 do
for b from a to (N-a)/2 do
if igcd(a,b) > 1 then next fi;
ab:= a*b;
for c from b to N-a-b do
if igcd(ab,c)=1 then A[a+b+c]:= A[a+b+c]+1 fi
od od od:
convert(A,list); # Robert Israel, May 09 2019
-
Table[Sum[Sum[Floor[1/(GCD[i, j] GCD[j, n - i - j] GCD[i, n - i - j])], {i, j, Floor[(n - j)/2]}], {j, Floor[n/3]}], {n, 0, 100}]
Table[Length[Select[IntegerPartitions[n,{3}],CoprimeQ@@#&]],{n,0,100}] (* Gus Wiseman, Oct 15 2020 *)
A337561
Number of pairwise coprime strict compositions of n, where a singleton is not considered coprime unless it is (1).
Original entry on oeis.org
1, 1, 0, 2, 2, 4, 8, 6, 16, 12, 22, 40, 40, 66, 48, 74, 74, 154, 210, 228, 242, 240, 286, 394, 806, 536, 840, 654, 1146, 1618, 2036, 2550, 2212, 2006, 2662, 4578, 4170, 7122, 4842, 6012, 6214, 11638, 13560, 16488, 14738, 15444, 16528, 25006, 41002, 32802
Offset: 0
The a(1) = 1 through a(9) = 12 compositions (empty column shown as dot):
(1) . (1,2) (1,3) (1,4) (1,5) (1,6) (1,7) (1,8)
(2,1) (3,1) (2,3) (5,1) (2,5) (3,5) (2,7)
(3,2) (1,2,3) (3,4) (5,3) (4,5)
(4,1) (1,3,2) (4,3) (7,1) (5,4)
(2,1,3) (5,2) (1,2,5) (7,2)
(2,3,1) (6,1) (1,3,4) (8,1)
(3,1,2) (1,4,3) (1,3,5)
(3,2,1) (1,5,2) (1,5,3)
(2,1,5) (3,1,5)
(2,5,1) (3,5,1)
(3,1,4) (5,1,3)
(3,4,1) (5,3,1)
(4,1,3)
(4,3,1)
(5,1,2)
(5,2,1)
A072706 counts unimodal strict compositions.
A220377*6 counts these compositions of length 3.
A337462 is the not necessarily strict version.
A000740 counts relatively prime compositions, with strict case
A332004.
A051424 counts pairwise coprime or singleton partitions.
A101268 considers all singletons to be coprime, with strict case
A337562.
A178472 counts compositions with a common factor > 1.
A328673 counts pairwise non-coprime partitions.
A333228 ranks compositions whose distinct parts are pairwise coprime.
-
Table[Length[Select[Join@@Permutations/@IntegerPartitions[n],#=={}||UnsameQ@@#&&CoprimeQ@@#&]],{n,0,10}]
A337485
Number of pairwise coprime integer partitions of n with no 1's, where a singleton is not considered coprime unless it is (1).
Original entry on oeis.org
0, 0, 0, 0, 0, 1, 0, 2, 1, 2, 2, 4, 3, 5, 4, 4, 7, 8, 9, 10, 10, 9, 13, 17, 18, 17, 19, 19, 24, 29, 34, 33, 31, 31, 42, 42, 56, 55, 50, 54, 66, 77, 86, 86, 79, 81, 96, 124, 127, 126, 127, 126, 145, 181, 190, 184, 183, 192, 212, 262, 289, 278, 257, 270, 311
Offset: 0
The a(n) partitions for n = 5, 7, 12, 13, 16, 17, 18, 19 (A..H = 10..17):
(3,2) (4,3) (7,5) (7,6) (9,7) (9,8) (B,7) (A,9)
(5,2) (5,4,3) (8,5) (B,5) (A,7) (D,5) (B,8)
(7,3,2) (9,4) (D,3) (B,6) (7,6,5) (C,7)
(A,3) (7,5,4) (C,5) (8,7,3) (D,6)
(B,2) (8,5,3) (D,4) (9,5,4) (E,5)
(9,5,2) (E,3) (9,7,2) (F,4)
(B,3,2) (F,2) (B,4,3) (G,3)
(7,5,3,2) (B,5,2) (H,2)
(D,3,2) (B,5,3)
(7,5,4,3)
A007359 considers all singletons to be coprime.
A337452 is the relatively prime instead of pairwise coprime version, with non-strict version
A302698.
A337563 is the restriction to partitions of length 3.
A002865 counts partitions with no 1's.
A078374 counts relatively prime strict partitions.
-
Table[Length[Select[IntegerPartitions[n],!MemberQ[#,1]&&CoprimeQ@@#&]],{n,0,30}]
A318717
Number of strict integer partitions of n in which no two parts are relatively prime.
Original entry on oeis.org
1, 1, 1, 1, 1, 1, 2, 1, 2, 2, 3, 1, 5, 1, 5, 4, 6, 1, 10, 1, 11, 6, 12, 1, 19, 3, 18, 8, 23, 1, 36, 2, 32, 13, 38, 7, 57, 2, 54, 19, 68, 3, 95, 3, 90, 33, 104, 3, 148, 7, 149, 40, 166, 5, 230, 17, 226, 56, 256, 6, 360, 9, 340, 84, 390, 25, 527, 11, 513, 109
Offset: 0
The a(20) = 11 partitions:
(20),
(12,8), (14,6), (15,5), (16,4), (18,2),
(10,6,4), (10,8,2), (12,6,2), (14,4,2),
(8,6,4,2).
Cf.
A000009,
A007359,
A007360,
A051185,
A302569,
A302797,
A303140,
A303280,
A303283,
A305713,
A305843,
A305854,
A305713,
A318715,
A318719.
-
Table[Length[Select[IntegerPartitions[n],And[UnsameQ@@#,And@@(GCD[##]>1&)@@@Select[Tuples[#,2],Less@@#&]]&]],{n,30}]
A337462
Number of pairwise coprime compositions of n, where a singleton is not considered coprime unless it is (1).
Original entry on oeis.org
1, 1, 1, 3, 6, 12, 21, 37, 62, 100, 159, 253, 402, 634, 983, 1491, 2224, 3280, 4813, 7043, 10270, 14888, 21415, 30585, 43400, 61204, 85747, 119295, 164834, 226422, 309663, 422301, 574826, 781236, 1060181, 1436367, 1942588, 2622078, 3531151, 4742315, 6348410
Offset: 0
The a(1) = 1 through a(5) = 12 compositions:
(1) (1,1) (1,2) (1,3) (1,4)
(2,1) (3,1) (2,3)
(1,1,1) (1,1,2) (3,2)
(1,2,1) (4,1)
(2,1,1) (1,1,3)
(1,1,1,1) (1,3,1)
(3,1,1)
(1,1,1,2)
(1,1,2,1)
(1,2,1,1)
(2,1,1,1)
(1,1,1,1,1)
A000740 counts the relatively prime instead of pairwise coprime version.
A101268 considers all singletons to be coprime, with strict case
A337562.
A337461 counts these compositions of length 3.
A051424 counts pairwise coprime or singleton partitions.
A101268 counts pairwise coprime or singleton compositions.
A178472 counts compositions with a common factor.
A305713 counts strict pairwise coprime partitions.
A328673 counts pairwise non-coprime partitions.
A333228 ranks compositions whose distinct parts are pairwise coprime.
A337667 counts pairwise non-coprime compositions.
-
Table[Length[Select[Join@@Permutations/@IntegerPartitions[n],#=={}||CoprimeQ@@#&]],{n,0,10}]
A324751
Number of strict integer partitions of n containing no prime indices of the parts.
Original entry on oeis.org
1, 1, 1, 1, 2, 1, 3, 3, 2, 4, 5, 5, 6, 8, 8, 12, 10, 14, 13, 18, 19, 26, 25, 30, 34, 39, 40, 51, 55, 60, 71, 77, 90, 97, 111, 123, 136, 153, 170, 179, 216, 230, 264, 282, 322, 345, 385, 423, 470, 513, 573, 629, 686, 755, 834, 910, 1005, 1095, 1194, 1303, 1433
Offset: 0
The a(1) = 1 through a(13) = 8 strict integer partitions (A...D = 10...13):
1 2 3 4 5 6 7 8 9 A B C D
31 42 43 71 54 64 65 75 76
51 52 63 73 83 84 85
72 82 542 93 94
91 731 A2 B2
B1 643
751
931
Cf.
A000720,
A001462,
A007097,
A074971,
A078374,
A112798,
A276625,
A290822,
A305713,
A306844,
A324764.
-
Table[Length[Select[IntegerPartitions[n],UnsameQ@@#&&Intersection[#,PrimePi/@First/@Join@@FactorInteger/@#]=={}&]],{n,0,30}]
Showing 1-10 of 46 results.
Comments