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A324926
Numbers not divisible by any prime indices of their prime indices.
11
1, 2, 4, 5, 8, 11, 16, 17, 22, 23, 25, 31, 32, 34, 41, 44, 47, 55, 59, 62, 64, 67, 73, 82, 83, 85, 88, 97, 103, 109, 115, 118, 121, 124, 125, 127, 128, 134, 137, 149, 157, 164, 166, 167, 176, 179, 187, 191, 194, 197, 205, 211, 218, 227, 233, 235, 236, 241, 242
OFFSET
1,2
COMMENTS
A prime index of n is a number m such that prime(m) divides n. For example, the prime indices of 55 are {3,5} with prime indices {{2},{3}}. Since 55 is not divisible by 2 or 3, it belongs to the sequence.
LINKS
EXAMPLE
The sequence of multisets of multisets whose MM-numbers (see A302242) belong to the sequence begins:
1: {}
2: {{}}
4: {{},{}}
5: {{2}}
8: {{},{},{}}
11: {{3}}
16: {{},{},{},{}}
17: {{4}}
22: {{},{3}}
23: {{2,2}}
25: {{2},{2}}
31: {{5}}
32: {{},{},{},{},{}}
34: {{},{4}}
41: {{6}}
44: {{},{},{3}}
47: {{2,3}}
55: {{2},{3}}
59: {{7}}
62: {{},{5}}
64: {{},{},{},{},{},{}}
MATHEMATICA
primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
Select[Range[100], And@@Table[!Divisible[#, i], {i, Union@@primeMS/@primeMS[#]}]&]
KEYWORD
nonn
AUTHOR
Gus Wiseman, Mar 21 2019
STATUS
approved