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 A218574 #11 Jul 04 2020 05:50:41 %S A218574 32318,45807,110443,123932,188568,202057,266693,280182,344818,358307, %T A218574 422943,436432,501068,514557,579193,592682,657318,670807,735443, %U A218574 748932,813568,827057,891693,905182,969818,983307 %N A218574 Numbers k such that k^2 + 1 is divisible by a 7th power. %H A218574 Amiram Eldar, <a href="/A218574/b218574.txt">Table of n, a(n) for n = 1..10000</a> %e A218574 32318 is in the sequence because 32318^2 + 1 = 5 ^ 7 * 29 * 461. %e A218574 6826318 is in the sequence because 6826318^2 + 1 = 5 ^ 3 * 13 ^ 8 * 457. %t A218574 Select[Range[2,1500000],Max[Transpose[FactorInteger[#^2+1]][[2]]]>6&] %Y A218574 Cf. A002522, A049532, A034939, A218562, A218563, A218564, A218565. %Y A218574 Cf. A001015 (7th powers). %K A218574 nonn %O A218574 1,1 %A A218574 _Michel Lagneau_, Nov 02 2012