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A383514
Heinz numbers of non Wilf section-sum partitions.
7
10, 14, 15, 22, 26, 33, 34, 35, 38, 39, 46, 51, 55, 57, 58, 62, 65, 69, 74, 77, 82, 85, 86, 87, 91, 93, 94, 95, 100, 106, 111, 115, 118, 119, 122, 123, 129, 130, 133, 134, 141, 142, 143, 145, 146, 155, 158, 159, 161, 166, 170, 177, 178, 182, 183, 185, 187, 190
OFFSET
1,1
COMMENTS
First differs from A384007 in having 1000.
The Heinz number of a partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k). This gives a bijective correspondence between positive integers and integer partitions.
An integer partition is Wilf iff its multiplicities are all different, ranked by A130091.
An integer partition is section-sum iff it is possible to choose a disjoint family of strict partitions, one of each of its positive 0-appended differences. These are ranked by A381432.
EXAMPLE
The terms together with their prime indices begin:
10: {1,3} 57: {2,8} 94: {1,15}
14: {1,4} 58: {1,10} 95: {3,8}
15: {2,3} 62: {1,11} 100: {1,1,3,3}
22: {1,5} 65: {3,6} 106: {1,16}
26: {1,6} 69: {2,9} 111: {2,12}
33: {2,5} 74: {1,12} 115: {3,9}
34: {1,7} 77: {4,5} 118: {1,17}
35: {3,4} 82: {1,13} 119: {4,7}
38: {1,8} 85: {3,7} 122: {1,18}
39: {2,6} 86: {1,14} 123: {2,13}
46: {1,9} 87: {2,10} 129: {2,14}
51: {2,7} 91: {4,6} 130: {1,3,6}
55: {3,5} 93: {2,11} 133: {4,8}
MATHEMATICA
disjointFamilies[y_]:=Select[Tuples[IntegerPartitions/@Length/@Split[y]], UnsameQ@@Join@@#&];
prix[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
conj[y_]:=If[Length[y]==0, y, Table[Length[Select[y, #>=k&]], {k, 1, Max[y]}]];
Select[Range[100], disjointFamilies[conj[prix[#]]]!={}&&!UnsameQ@@Last/@FactorInteger[#]&]
CROSSREFS
Ranking sequences are shown in parentheses below.
For Look-and-Say instead of section-sum we have A351592 (A384006).
These partitions are counted by A383506.
The Look-and-Say case is A383511 (A383518).
For Wilf instead of non Wilf we have A383519 (A383520).
A055396 gives least prime index, greatest A061395.
A056239 adds up prime indices, row sums of A112798, counted by A001222.
A098859 counts Wilf partitions (A130091), conjugate (A383512).
A122111 represents conjugation in terms of Heinz numbers.
A239455 counts section-sum partitions (A381432), complement A351293 (A381433).
A336866 counts non Wilf partitions (A130092), conjugate (A383513).
A381431 is the section-sum transform.
A383508 counts partitions that are both Look-and-Say and section-sum (A383515).
A383509 counts partitions that are Look-and-Say but not section-sum (A383516).
A383509 counts partitions that are not Look-and-Say but are section-sum (A384007).
A383510 counts partitions that are neither Look-and-Say nor section-sum (A383517).
Sequence in context: A271568 A229271 A088711 * A384007 A154774 A162708
KEYWORD
nonn
AUTHOR
Gus Wiseman, May 18 2025
STATUS
approved