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A339911 Numbers k > 1 for which bigomega(k) <= bigomega(k-1)/2, where bigomega gives the number of prime factors, counted with multiplicity. 4
5, 7, 11, 13, 17, 19, 23, 25, 29, 31, 33, 37, 41, 43, 47, 49, 53, 55, 57, 59, 61, 65, 67, 71, 73, 79, 82, 83, 85, 89, 91, 97, 101, 103, 107, 109, 113, 121, 127, 129, 131, 133, 137, 139, 141, 145, 149, 151, 157, 161, 163, 167, 169, 173, 177, 179, 181, 185, 191, 193, 197, 199, 201, 205, 209, 211, 217, 221, 223, 226, 227 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
Select[Range[3, 227, 2], PrimeOmega[#] <= PrimeOmega[# - 1]/2 &] (* Michael De Vlieger, Dec 22 2020 *)
PROG
(PARI) isA339911(n) = ((n>1)&&((2*bigomega(n))<=bigomega(n-1)));
CROSSREFS
Cf. A001222.
Subsequence of A339910.
Cf. A339908, A339912 for subsequences.
Sequence in context: A106571 A067291 A286265 * A007310 A069040 A070191
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 22 2020
STATUS
approved

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Last modified April 14 17:14 EDT 2024. Contains 371666 sequences. (Running on oeis4.)