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A344586
Numbers k for which A003415(k) >= A001065(k), where A003415 gives the arithmetic derivative, and A001065 is the sum of proper divisors.
3
1, 2, 3, 4, 5, 7, 8, 9, 11, 12, 13, 16, 17, 18, 19, 20, 23, 24, 25, 27, 28, 29, 31, 32, 36, 37, 40, 41, 43, 44, 45, 47, 48, 49, 50, 52, 53, 54, 56, 59, 61, 63, 64, 67, 68, 71, 72, 73, 75, 76, 79, 80, 81, 83, 88, 89, 92, 96, 97, 98, 99, 100, 101, 103, 104, 107, 108, 109, 112, 113, 116, 117, 120, 121, 124, 125, 127, 128, 131
OFFSET
1,2
LINKS
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
isA344586(n) = (A003415(n) >= (sigma(n)-n));
CROSSREFS
Cf. A212127, A212128 (subsequences), A344585 (complement).
Positions of nonnegative terms in A211991.
Differs from A212165 for the first time at n=121, where a(121) = 220, while A212165(121) = 223.
Sequence in context: A363597 A212165 A367685 * A319161 A325370 A329139
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 24 2021
STATUS
approved