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%I #11 Oct 26 2023 00:44:02
%S 1,5,19,25,47,61,89,95,103,125,131,173,229,235,257,271,305,313,361,
%T 383,397,439,445,467,475,509,515,523,593,607,625,655,677,691,719,733,
%U 761,859,865,887,893,929,971,1013
%N Divisible only by primes congruent to 5 mod 7.
%H Vincenzo Librandi, <a href="/A004623/b004623.txt">Table of n, a(n) for n = 1..1000</a>
%t ok[1]=True;ok[n_]:=And@@(Mod[#,7]==5&)/@FactorInteger[n][[All,1]];Select[Range[5000],ok] (* _Vincenzo Librandi_, Aug 20 2012 *)
%o (Magma) [n: n in [1..2000] | forall{d: d in PrimeDivisors(n) | d mod 7 eq 5}]; // _Vincenzo Librandi_, Aug 20 2012
%K nonn
%O 1,2
%A _N. J. A. Sloane_
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