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 A325412 Number of distinct omega-sequences of integer partitions of n. 3
 1, 1, 2, 3, 5, 5, 10, 9, 14, 15, 20, 21, 33, 30, 39, 45, 54, 54, 69, 68, 85, 90, 100, 104, 128, 127, 141, 153, 172, 175, 205, 203, 229, 240, 257, 274, 308, 309, 335, 356, 390, 395, 437, 444, 481, 506, 530, 549, 602, 609, 648, 672, 710, 727, 777, 798, 848, 871 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS The omega-sequence of an integer partition is the sequence of lengths of the multisets obtained by repeatedly taking the multiset of multiplicities until a singleton is reached. For example, the partition (32211) has chain of multisets of multiplicities {1,1,2,2,3} -> {1,2,2} -> {1,2} -> {1,1} -> {2}, so its omega-sequence is (5,3,2,2,1). LINKS EXAMPLE The a(1) = 1 through a(9) = 15 omega-sequences: (1) (1) (1) (1) (1) (1) (1) (1) (1) (21) (31) (21) (51) (21) (71) (21) (31) (221) (41) (221) (31) (221) (41) (91) (221) (3221) (61) (331) (81) (221) (3221) (4221) (221) (3221) (221) (331) (331) (4221) (331) (621) (421) (5221) (421) (3221) (3221) (6221) (3221) (4221) (4221) (43221) (4221) (5221) (5221) (5221) (6221) (6221) (7221) (7221) (8221) (43221) (43221) (53221) (53221) (63221) MATHEMATICA omseq[ptn_List]:=If[ptn=={}, {}, Length/@NestWhileList[Sort[Length/@Split[#]]&, ptn, Length[#]>1&]]; Table[Length[Union[omseq/@IntegerPartitions[n]]], {n, 0, 30}] CROSSREFS Cf. A181819, A225486, A323014, A323023, A325238, A325248, A325277, A325413, A325415. Integer partition triangles: A008284 (first omega), A116608 (second omega), A325242 (third omega), A325268 (second-to-last omega), A225485 or A325280 (frequency depth), A325414 (omega-sequence sum). Sequence in context: A338750 A265822 A257012 * A265562 A140312 A088887 Adjacent sequences: A325409 A325410 A325411 * A325413 A325414 A325415 KEYWORD nonn AUTHOR Gus Wiseman, Apr 24 2019 STATUS approved

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Last modified March 29 01:21 EDT 2023. Contains 361596 sequences. (Running on oeis4.)