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%I #11 Sep 23 2017 20:20:19
%S 5,11,17,23,29,31,41,47,53,59,61,71,73,83,89,101,107,113,131,137,139,
%T 149,151,157,167,173,179,181,191,197,199,211,227,233,239,241,251,257,
%U 263,269,271,281,283,293,311,317,331,337,347,353,359,367,373,383,389
%N Largest primes < numbers of the form 6k (duplicates removed).
%e 11 is in the sequence because 11 is the largest prime < 12 = 6*2.
%t PrevPrim[n_] := Block[{k = n - 1}, While[ !PrimeQ[k], k-- ]; k]; Union[ Table[ PrevPrim[6n], {n, 65}]] (* _Robert G. Wilson v_, May 21 2005 *)
%t NextPrime[#,-1]&/@(6*Range[100])//Union (* _Harvey P. Dale_, Sep 23 2017 *)
%Y Cf. A105399.
%K easy,nonn
%O 1,1
%A _Giovanni Teofilatto_, May 03 2005
%E Corrected and extended by _Robert G. Wilson v_, May 21 2005
%E Edited, corrected and extended by _Ray Chandler_, Oct 17 2006