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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A367215 Number of strict integer partitions of n whose length (number of parts) is not equal to the sum of any subset.

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%I A367215 #11 Nov 14 2023 09:50:32
%S A367215 0,0,1,1,2,2,2,3,3,4,5,7,8,10,12,15,18,21,25,29,34,40,46,53,62,71,82,
%T A367215 95,109,124,143,162,185,210,240,270,308,347,393,443,500,562,634,711,
%U A367215 798,895,1002,1120,1252,1397,1558,1735,1930,2146,2383,2644,2930,3245
%N A367215 Number of strict integer partitions of n whose length (number of parts) is not equal to the sum of any subset.
%C A367215 These partitions have Heinz numbers A367225 /\ A005117.
%H A367215 Chai Wah Wu, <a href="/A367215/b367215.txt">Table of n, a(n) for n = 0..118</a>
%e A367215 The a(2) = 1 through a(11) = 7 strict partitions:
%e A367215   (2)  (3)  (4)    (5)    (6)    (7)    (8)    (9)    (10)     (11)
%e A367215             (3,1)  (4,1)  (5,1)  (4,3)  (5,3)  (5,4)  (6,4)    (6,5)
%e A367215                                  (6,1)  (7,1)  (6,3)  (7,3)    (7,4)
%e A367215                                                (8,1)  (9,1)    (8,3)
%e A367215                                                       (5,4,1)  (10,1)
%e A367215                                                                (5,4,2)
%e A367215                                                                (6,4,1)
%e A367215 The a(2) = 1 through a(15) = 15 strict partitions (A..F = 10..15):
%e A367215   2  3  4   5   6   7   8   9   A    B    C    D    E     F
%e A367215         31  41  51  43  53  54  64   65   75   76   86    87
%e A367215                     61  71  63  73   74   84   85   95    96
%e A367215                             81  91   83   93   94   A4    A5
%e A367215                                 541  A1   B1   A3   B3    B4
%e A367215                                      542  642  C1   D1    C3
%e A367215                                      641  651  652  752   E1
%e A367215                                           741  742  761   654
%e A367215                                                751  842   762
%e A367215                                                841  851   852
%e A367215                                                     941   861
%e A367215                                                     6521  942
%e A367215                                                           951
%e A367215                                                           A41
%e A367215                                                           7521
%t A367215 Table[Length[Select[IntegerPartitions[n], UnsameQ@@#&&FreeQ[Total/@Subsets[#], Length[#]]&]], {n,0,30}]
%Y A367215 The following sequences count and rank integer partitions and finite sets according to whether their length is a subset-sum or linear combination of the parts. The current sequence is starred.
%Y A367215                sum-full   sum-free   comb-full  comb-free
%Y A367215               -------------------------------------------
%Y A367215   partitions:  A367212    A367213    A367218    A367219
%Y A367215   strict:      A367214    A367215*   A367220    A367221
%Y A367215   subsets:     A367216    A367217    A367222    A367223
%Y A367215   ranks:       A367224    A367225    A367226    A367227
%Y A367215 A000041 counts integer partitions, strict A000009.
%Y A367215 A007865/A085489/A151897 count certain types of sum-free subsets.
%Y A367215 A124506 appears to count combination-free subsets, differences of A326083.
%Y A367215 A188431 counts complete strict partitions, incomplete A365831.
%Y A367215 A237667 counts sum-free partitions, ranks A364531.
%Y A367215 A240861 counts strict partitions with length not a part, complement A240855.
%Y A367215 A275972 counts strict knapsack partitions, non-strict A108917.
%Y A367215 A364349 counts sum-free strict partitions, sum-full A364272.
%Y A367215 Triangles:
%Y A367215 A008289 counts strict partitions by length, non-strict A008284.
%Y A367215 A365661 counts strict partitions with a subset-sum k, non-strict A365543.
%Y A367215 A365663 counts strict partitions without a subset-sum k, non-strict A046663.
%Y A367215 A365832 counts strict partitions by subset-sums, non-strict A365658.
%Y A367215 Cf. A002865, A229816, A238628, A364346, A364350, A365312, A365922, A366320.
%K A367215 nonn
%O A367215 0,5
%A A367215 _Gus Wiseman_, Nov 12 2023