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A004616 Divisible only by primes congruent to 2 mod 5. 4

%I

%S 1,2,4,7,8,14,16,17,28,32,34,37,47,49,56,64,67,68,74,94,97,98,107,112,

%T 119,127,128,134,136,137,148,157,167,188,194,196,197,214,224,227,238,

%U 254,256,257,259,268,272,274

%N Divisible only by primes congruent to 2 mod 5.

%H Vincenzo Librandi, <a href="/A004616/b004616.txt">Table of n, a(n) for n = 1..1000</a>

%t ok[1] = True; ok[n_] := And@@ (Mod[#, 5] == 2 &)/@ FactorInteger[n][[All,1]]; Select[Range[2000],ok] (* _Vincenzo Librandi_, Aug 11 2012 *)

%o (MAGMA) [n: n in [1..300] | forall{d: d in PrimeDivisors(n) | d mod 5 eq 2}]; // _Bruno Berselli_, Aug 11 2012

%K nonn

%O 1,2

%A _N. J. A. Sloane_.

%E Offset changed from 0 to 1 by _Vincenzo Librandi_, Aug 20 2012

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Last modified October 26 05:58 EDT 2021. Contains 348257 sequences. (Running on oeis4.)