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%I A067784 #17 Feb 11 2021 01:40:41
%S A067784 1,2,3,4,5,6,8,10,12,15,16,20,24,29,30,40,45,48,56,60,64,65,80,92,105,
%T A067784 111,120,144,146,160,180,182,212,232,240,246,336,340,344,348,360,376,
%U A067784 439,470,476,580,624,680,709,819,832,914,984,1020,1058,1290,1341,1352
%N A067784 Numbers k such that prime(k+1)^4 == prime(k)^4 (mod k).
%H A067784 Robert Israel, <a href="/A067784/b067784.txt">Table of n, a(n) for n = 1..300</a>
%p A067784 q:= 2: count:= 0:
%p A067784 for n from 1 while count < 100 do
%p A067784   p:= q; q:= nextprime(p);
%p A067784   if q^4 - p^4 mod n = 0 then count:= count+1; A[count]:= n; fi;
%p A067784 od:
%p A067784 seq(A[i],i=1..count); # _Robert Israel_, May 16 2017
%t A067784 Select[Range[100], Mod[Prime[# + 1]^4 , #] == Mod[Prime[#]^4, #] &] (* _G. C. Greubel_, May 17 2017 *)
%Y A067784 Cf. A030514, A067785.
%K A067784 nonn
%O A067784 1,2
%A A067784 _Benoit Cloitre_, Feb 06 2002

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