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.
%I A364674 #9 Aug 06 2023 08:17:52 %S A364674 1,1,2,3,4,4,8,7,11,13,17,18,32,30,44,54,70,78,114,125,171,205,257, %T A364674 302,408,464,592,711,892,1042,1330,1543,1925,2279,2787,3291,4061,4727, %U A364674 5753,6792,8197,9583,11593,13505,16198,18965,22548,26290,31340,36363,43046 %N A364674 Number of integer partitions of n containing all of their own nonzero first differences. %e A364674 The partition (10,5,3,3,2,1) has nonzero differences (5,2,1,1) so is counted under a(24). %e A364674 The a(1) = 1 through a(9) = 13 partitions: %e A364674 (1) (2) (3) (4) (5) (6) (7) (8) (9) %e A364674 (11) (21) (22) (221) (33) (421) (44) (63) %e A364674 (111) (211) (2111) (42) (2221) (422) (333) %e A364674 (1111) (11111) (222) (3211) (2222) (3321) %e A364674 (321) (22111) (3221) (4221) %e A364674 (2211) (211111) (4211) (22221) %e A364674 (21111) (1111111) (22211) (32211) %e A364674 (111111) (32111) (42111) %e A364674 (221111) (222111) %e A364674 (2111111) (321111) %e A364674 (11111111) (2211111) %e A364674 (21111111) %e A364674 (111111111) %t A364674 Table[Length[Select[IntegerPartitions[n], SubsetQ[#,Differences[Union[#]]]&]],{n,0,30}] %Y A364674 For no differences we have A363260, subsets A364463, strict A364464. %Y A364674 For at least one difference we have A364467, ranks A364537, strict A364536. %Y A364674 For subsets instead of partitions we have A364671, complement A364672. %Y A364674 The strict case (no differences of 0) is counted by A364673. %Y A364674 For submultisets instead of subsets we have A364675. %Y A364674 A000041 counts integer partitions, strict A000009. %Y A364674 A008284 counts partitions by length, strict A008289. %Y A364674 A236912 counts sum-free partitions w/o re-used parts, complement A237113. %Y A364674 A325325 counts partitions with distinct first differences. %Y A364674 Cf. A002865, A007862, A025065, A229816, A237667, A320347, A326083, A363225, A364272, A364466. %K A364674 nonn %O A364674 0,3 %A A364674 _Gus Wiseman_, Aug 04 2023