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A159973 Non-refactorable numbers: number of divisors of n does not divide n. 2
3, 4, 5, 6, 7, 10, 11, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 38, 39, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 81, 82, 83, 85 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
Select[Range[100], Mod[#, DivisorSigma[0, #]]!=0&] (* Harvey P. Dale, Aug 31 2023 *)
PROG
(Magma) [ n: n in [1..85] | n mod #Divisors(n) ne 0 ];
CROSSREFS
Complement of A033950.
Sequence in context: A092860 A351392 A112874 * A359772 A158008 A106155
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Apr 28 2009
EXTENSIONS
Edited and extended by Klaus Brockhaus, Apr 29 2009
STATUS
approved

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Last modified June 14 05:27 EDT 2024. Contains 373393 sequences. (Running on oeis4.)