A237668 Number of partitions of n such that some part is a sum of two or more other parts.
0, 0, 0, 0, 1, 1, 4, 4, 10, 13, 23, 27, 49, 60, 93, 115, 170, 210, 300, 370, 510, 632, 846, 1031, 1359, 1670, 2159, 2630, 3355, 4082, 5130, 6220, 7739, 9360, 11555, 13889, 16991, 20402, 24824, 29636, 35855, 42707, 51309, 60955, 72896, 86328, 102826, 121348
Offset: 0
Keywords
Examples
a(6) = 4 counts these partitions: 123, 1113, 1122, 11112. From _Gus Wiseman_, Aug 12 2023: (Start) The a(0) = 0 through a(9) = 13 partitions: . . . . (211) (2111) (321) (3211) (422) (3321) (2211) (22111) (431) (4221) (3111) (31111) (3221) (4311) (21111) (211111) (4211) (5211) (22211) (32211) (32111) (33111) (41111) (42111) (221111) (222111) (311111) (321111) (2111111) (411111) (2211111) (3111111) (21111111) (End)
Links
- Giovanni Resta, Table of n, a(n) for n = 0..100
- Giovanni Resta, C program for computing a(0)-a(100)
Crossrefs
Programs
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Mathematica
z = 20; m = Map[Count[Map[MemberQ[#, Apply[Alternatives, Map[Apply[Plus, #] &, DeleteDuplicates[DeleteCases[Subsets[#], _?(Length[#] < 2 &)]]]]] &, IntegerPartitions[#]], False] &, Range[z]]; PartitionsP[Range[z]] - m (* Peter J. C. Moses, Feb 10 2014 *) Table[Length[Select[IntegerPartitions[n],Intersection[#,Total/@Subsets[#,{2,Length[#]}]]!={}&]],{n,0,15}] (* Gus Wiseman, Aug 12 2023 *)
Extensions
a(21)-a(47) from Giovanni Resta, Feb 22 2014
Comments