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A327784
Heinz numbers of integer partitions whose LCM is greater than their sum.
4
1, 15, 33, 35, 51, 55, 66, 69, 70, 77, 85, 91, 93, 95, 99, 102, 105, 110, 119, 123, 132, 138, 140, 141, 143, 145, 153, 154, 155, 161, 165, 170, 175, 177, 182, 186, 187, 190, 201, 203, 204, 205, 207, 209, 210, 215, 217, 219, 220, 221, 231, 238, 245, 246, 247, 249
OFFSET
1,2
COMMENTS
The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).
FORMULA
A290103(a(k)) > A056239(a(k)).
EXAMPLE
The sequence of terms together with their prime indices begins:
1: {}
15: {2,3}
33: {2,5}
35: {3,4}
51: {2,7}
55: {3,5}
66: {1,2,5}
69: {2,9}
70: {1,3,4}
77: {4,5}
85: {3,7}
91: {4,6}
93: {2,11}
95: {3,8}
99: {2,2,5}
102: {1,2,7}
105: {2,3,4}
110: {1,3,5}
119: {4,7}
123: {2,13}
132: {1,1,2,5}
MAPLE
q:= n-> (l-> is(ilcm(l[])>add(j, j=l)))(map(i->
numtheory[pi](i[1])$i[2], ifactors(n)[2])):
select(q, [$1..250])[]; # Alois P. Heinz, Sep 27 2019
MATHEMATICA
primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
Select[Range[2, 100], LCM@@primeMS[#]>Total[primeMS[#]]&]
CROSSREFS
The enumeration of these partitions by sum is A327779.
Heinz numbers of partitions whose LCM is twice their sum are A327775.
Heinz numbers of partitions whose LCM is less than their sum are A327776.
Heinz numbers of partitions whose LCM is a multiple their sum are A327783.
Sequence in context: A154369 A243592 A089966 * A339562 A338468 A337984
KEYWORD
nonn
AUTHOR
Gus Wiseman, Sep 25 2019
STATUS
approved