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A107747 Numbers n such that the least prime factor of 6*n+1 < the least prime factor of 6*n-1, A107744(n) < A107745(n). 3
4, 8, 9, 14, 15, 19, 22, 24, 28, 29, 34, 39, 42, 43, 44, 49, 50, 53, 54, 57, 59, 60, 64, 65, 67, 69, 74, 75, 78, 79, 80, 82, 84, 85, 89, 92, 93, 94, 98, 99, 104, 108, 109, 113, 114, 117, 119, 120, 124, 127, 129, 130, 133, 134, 139, 140, 144, 148, 149, 150, 152, 154 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
lpfQ[n_]:=Module[{c=6n}, FactorInteger[c+1][[1, 1]] < FactorInteger [c-1][[1, 1]]]; Select[Range[200], lpfQ] (* Harvey P. Dale, Apr 18 2011 *)
PROG
(PARI) isok(n) = vecmin(factor(6*n+1)[, 1]) < vecmin(factor(6*n-1)[, 1]);
for(n=1, 200, if(isok(n)==1, print1(n", "))) \\ Altug Alkan, Oct 23 2015
CROSSREFS
Cf. A107744 Smallest prime factor of 6*n+1; A107745 Smallest prime factor of 6*n-1; A107746 Values of n such that A107744(n) > A107745(n).
Sequence in context: A120512 A046954 A112775 * A121763 A110087 A312830
KEYWORD
nonn
AUTHOR
Zak Seidov, May 23 2005
EXTENSIONS
Comments corrected and (at the suggestion of Michel Marcus) moved to Crossrefs by Jason Kimberley, Oct 23 2015
STATUS
approved

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Last modified March 19 04:58 EDT 2024. Contains 370952 sequences. (Running on oeis4.)