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A326624
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Heinz numbers of non-constant integer partitions whose geometric mean is an integer.
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11
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14, 42, 46, 57, 76, 106, 126, 161, 183, 185, 194, 196, 228, 230, 302, 371, 378, 393, 399, 412, 424, 454, 477, 515, 588, 622, 679, 684, 687, 722, 742, 781, 786, 838, 1057, 1064, 1077, 1082, 1115, 1134, 1150, 1157, 1159, 1219, 1244, 1272, 1322, 1563, 1589, 1654
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OFFSET
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1,1
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COMMENTS
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The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).
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LINKS
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EXAMPLE
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The sequence of terms together with their prime indices begins:
14: {1,4}
42: {1,2,4}
46: {1,9}
57: {2,8}
76: {1,1,8}
106: {1,16}
126: {1,2,2,4}
161: {4,9}
183: {2,18}
185: {3,12}
194: {1,25}
196: {1,1,4,4}
228: {1,1,2,8}
230: {1,3,9}
302: {1,36}
371: {4,16}
378: {1,2,2,2,4}
393: {2,32}
399: {2,4,8}
412: {1,1,27}
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MATHEMATICA
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primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
Select[Range[100], !PrimePowerQ[#]&&IntegerQ[GeometricMean[primeMS[#]]]&]
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CROSSREFS
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The case with prime powers is A326623.
Subsets whose geometric mean is an integer are A326027.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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