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 A374600 #11 Jul 17 2024 11:42:28 %S A374600 1,4,9,2,16,25,36,8,3,49,64,18,81,100,121,5,144,12,169,32,196,225,256, %T A374600 50,6,289,27,72,324,361,400,20,441,484,529,7,576,625,676,98,729,784, %U A374600 841,128,48,900,961,45,10,24,1024,162,1089,75,1156,200,1225,1296 %N A374600 If n = i^2 * A005117(j) for some i, j > 0 then a(n) = j^2 * A005117(i). %C A374600 This sequence is a self-inverse permutation of the positive integers with infinitely many fixed points. %H A374600 Rémy Sigrist, <a href="/A374600/b374600.txt">Table of n, a(n) for n = 1..10000</a> %H A374600 Rémy Sigrist, <a href="/A374600/a374600.gp.txt">PARI program</a> %H A374600 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A374600 a(A249327(n, k)) = A249327(k, n). %F A374600 a(n) = n iff n = k^2 * A005117(k) for some k > 0. %e A374600 For n = 84: 84 = 2^2 * A005117(14), so a(84) = 14^2 * A005117(2) = 392. %o A374600 (PARI) \\ See Links section. %Y A374600 See A374611 for a similar sequence. %Y A374600 Cf. A000188, A005117, A007913, A249327. %K A374600 nonn %O A374600 1,2 %A A374600 _Rémy Sigrist_, Jul 13 2024