A237667 Number of partitions of n such that no part is a sum of two or more other parts.
1, 1, 2, 3, 4, 6, 7, 11, 12, 17, 19, 29, 28, 41, 42, 61, 61, 87, 85, 120, 117, 160, 156, 224, 216, 288, 277, 380, 363, 483, 474, 622, 610, 783, 755, 994, 986, 1235, 1191, 1549, 1483, 1876, 1865, 2306, 2279, 2806, 2732, 3406, 3413, 4091, 4013, 4991, 4895, 5872
Offset: 0
Keywords
Examples
For n = 6, the nonqualifiers are 123, 1113, 1122, 11112, leaving a(6) = 7. From _Gus Wiseman_, Aug 09 2023: (Start) The partition y = (5,3,1,1) has submultiset (3,1,1) with sum in y, so is not counted under a(10). The partition y = (5,3,3,1) has no non-singleton submultiset with sum in y, so is counted under a(12). The a(1) = 1 through a(8) = 12 partitions: (1) (2) (3) (4) (5) (6) (7) (8) (11) (21) (22) (32) (33) (43) (44) (111) (31) (41) (42) (52) (53) (1111) (221) (51) (61) (62) (311) (222) (322) (71) (11111) (411) (331) (332) (111111) (421) (521) (511) (611) (2221) (2222) (4111) (3311) (1111111) (5111) (11111111) (End)
Links
- Giovanni Resta, Table of n, a(n) for n = 0..100
- Giovanni Resta, C program for computing a(0)-a(100)
Crossrefs
These partitions have ranks A364531.
Programs
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Mathematica
Map[Count[Map[MemberQ[#,Apply[Alternatives,Map[Apply[Plus,#]&, DeleteDuplicates[DeleteCases[Subsets[#],?(Length[#]<2&)]]]]]&, IntegerPartitions[#]],False]&,Range[20]] (* _Peter J. C. Moses, Feb 10 2014 *) Table[Length[Select[IntegerPartitions[n],Intersection[#,Total/@Subsets[#,{2,Length[#]}]]=={}&]],{n,0,15}] (* Gus Wiseman, Aug 09 2023 *)
Extensions
a(21)-a(53) from Giovanni Resta, Feb 22 2014
Comments