A339911 Numbers k > 1 for which bigomega(k) <= bigomega(k-1)/2, where bigomega gives the number of prime factors, counted with multiplicity.

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

Offset

1,1

Links

Antti Karttunen, Table of n, a(n) for n = 1..17515; all terms <= 65537

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

Adjacent sequences: A339908 A339909 A339910 * A339912 A339913 A339914

Keyword

nonn

Author

Antti Karttunen, Dec 22 2020

Status

approved