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A340610
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Numbers whose number of prime factors (A001222) divides their greatest prime index (A061395).
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29
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2, 3, 5, 6, 7, 9, 11, 13, 14, 17, 19, 20, 21, 23, 26, 29, 30, 31, 35, 37, 38, 39, 41, 43, 45, 47, 49, 50, 52, 53, 56, 57, 58, 59, 61, 65, 67, 71, 73, 74, 75, 78, 79, 83, 84, 86, 87, 89, 91, 92, 95, 97, 101, 103, 106, 107, 109, 111, 113, 117, 122, 125, 126, 127
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OFFSET
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1,1
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COMMENTS
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A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798.
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LINKS
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FORMULA
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EXAMPLE
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The sequence of terms together with their prime indices begins:
2: {1} 29: {10} 56: {1,1,1,4}
3: {2} 30: {1,2,3} 57: {2,8}
5: {3} 31: {11} 58: {1,10}
6: {1,2} 35: {3,4} 59: {17}
7: {4} 37: {12} 61: {18}
9: {2,2} 38: {1,8} 65: {3,6}
11: {5} 39: {2,6} 67: {19}
13: {6} 41: {13} 71: {20}
14: {1,4} 43: {14} 73: {21}
17: {7} 45: {2,2,3} 74: {1,12}
19: {8} 47: {15} 75: {2,3,3}
20: {1,1,3} 49: {4,4} 78: {1,2,6}
21: {2,4} 50: {1,3,3} 79: {22}
23: {9} 52: {1,1,6} 83: {23}
26: {1,6} 53: {16} 84: {1,1,2,4}
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MAPLE
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filter:= proc(n) local F, m, g, t;
F:= ifactors(n)[2];
m:= add(t[2], t=F);
g:= numtheory:-pi(max(seq(t[1], t=F)));
g mod m = 0;
end proc:
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MATHEMATICA
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Select[Range[2, 100], Divisible[PrimePi[FactorInteger[#][[-1, 1]]], PrimeOmega[#]]&]
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CROSSREFS
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Note: Heinz numbers are given in parentheses below.
The case where all parts are multiples, not just the maximum part, is A143773 (A316428), with strict case A340830, while the case of factorizations is A340853.
These are the Heinz numbers of certain partitions counted by A168659.
A006141 counts partitions whose length equals their minimum (A324522).
A061395 selects the maximum prime index.
A112798 lists the prime indices of each positive integer.
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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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