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 A045586 #19 Oct 23 2021 10:06:35 %S A045586 1,2,5,25,55,58,125,155,275,605,625,775,1265,1375,1682,1705,3025,3125, %T A045586 3875,4805,6325,6655,6875,8525,13915,15125,15625,18755,19375,24025, %U A045586 29095,31625,33275,34375,39215,42625,48778,52855,53882,69575,73205 %N A045586 Numbers k that divide 7^k + 3^k. %H A045586 Amiram Eldar, <a href="/A045586/b045586.txt">Table of n, a(n) for n = 1..500</a> %t A045586 Select[Range[75000],Divisible[7^#+3^#,#]&] (* _Harvey P. Dale_, Apr 21 2019 *) %t A045586 Select[Range[75000], Divisible[PowerMod[7, #, #] + PowerMod[3, #, #], #] &] (* _Amiram Eldar_, Oct 23 2021 *) %Y A045586 Cf. A074608. %K A045586 nonn %O A045586 1,2 %A A045586 _David W. Wilson_