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A324587
Heinz numbers of integer partitions of n into distinct perfect squares (A033461).
14
1, 2, 7, 14, 23, 46, 53, 97, 106, 151, 161, 194, 227, 302, 311, 322, 371, 419, 454, 541, 622, 661, 679, 742, 827, 838, 1009, 1057, 1082, 1193, 1219, 1322, 1358, 1427, 1589, 1619, 1654, 1879, 2018, 2114, 2143, 2177, 2231, 2386, 2437, 2438, 2741, 2854, 2933
OFFSET
1,2
COMMENTS
The Heinz number of an integer partition (y_1, ..., y_k) is prime(y_1) * ... * prime(y_k).
Also products of distinct elements of A011757.
EXAMPLE
The sequence of terms together with their prime indices begins:
1: {}
2: {1}
7: {4}
14: {1,4}
23: {9}
46: {1,9}
53: {16}
97: {25}
106: {1,16}
151: {36}
161: {4,9}
194: {1,25}
227: {49}
302: {1,36}
311: {64}
322: {1,4,9}
371: {4,16}
419: {81}
454: {1,49}
541: {100}
MATHEMATICA
Select[Range[1000], And@@Cases[FactorInteger[#], {p_, k_}:>k==1&&IntegerQ[Sqrt[PrimePi[p]]]]&]
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 08 2019
STATUS
approved