This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A108200 #7 Nov 29 2019 04:01:51 %S A108200 5,7,62,19,1,31,2,1254,1692,85,912,49,20796,1,1234,627,50,846,4,860, %T A108200 28,456,4076,418,34,10398,564,21,91250,617,6,47670,304,25,6218,423, %U A108200 352018,2,6932,430,9348,14,400,228,2874,2038,324,209,12,17,5562,5199,25784,282 %N A108200 Least positive k such that k*n + 1 is a golden semiprime (A108540). %C A108200 Conjecture: for every n > 4 there exists a number k < n^[n/2] such that k*n + 1 is a golden semiprime, where [] is the floor function. %H A108200 Amiram Eldar, <a href="/A108200/b108200.txt">Table of n, a(n) for n = 1..1000</a> %e A108200 a(3) = 62 because 62*3+1 = 187 = 11*17 and 11*phi-17 = 0.7983... < 1. %t A108200 goldQ[n_] := Module[{f = FactorInteger[n]}, If[Length[f] != 2, False, If[Max[f[[;;,2]]] != 1, False, Abs[f[[2,1]] - f[[1,1]] * GoldenRatio] < 1]]]; a[n_] := Module[{k = 1}, While[!goldQ[k * n + 1], k++]; k]; Array[a, 54] (* _Amiram Eldar_, Nov 29 2019 *) %Y A108200 Cf. A108540. %K A108200 nonn %O A108200 1,1 %A A108200 _Jason Earls_, Jun 15 2005