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%I #8 Nov 28 2019 06:14:27
%S 3,5,11,31,37,47,157,571,911,1021,1487,2351,3571,24709,25463,69247,
%T 80803,216103,290141,465277,822691,1485373,1785473,3206767,14855327,
%U 27439609,28075231,84468479,107765599,161223523,218252393,788298307,1018470703,1527131129,2472296341
%N Greater prime factor of successively better golden semiprimes.
%C See A165569 and A165570 for the definition. Probably a subset of A108542.
%H Amiram Eldar, <a href="/A165572/b165572.txt">Table of n, a(n) for n = 1..48</a>
%F a(n) = A108539(A165569(n)).
%F a(n) = A165570(n)/A165571(n).
%t f[p_] := Module[{x = GoldenRatio * p, p1, p2}, p1 = NextPrime[x, -1]; p2 = NextPrime[p1]; If[p2 - x > x - p1, p1, p2]]; seq={}; dm = 1; p1 = 1; Do[p1 = NextPrime[p1]; k++; p2 = f[p1]; d = Abs[p2/p1 - GoldenRatio]; If[d < dm, dm = d; AppendTo[seq, p2]], {10^4}]; seq (* _Amiram Eldar_, Nov 28 2019 *)
%Y Cf. A108539, A165569, A165570, A165571.
%K nonn,more
%O 1,1
%A _Antti Karttunen_, Sep 22 2009
%E a(16)-a(23) from _Donovan Johnson_, May 13 2010
%E a(24)-a(35) from _Amiram Eldar_, Nov 28 2019
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