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 A046659 #23 Sep 24 2019 09:20:13 %S A046659 1,4,9,25,36,100,121,225,289,484,529,841,900,1089,1156,1681,2116,2209, %T A046659 2601,2809,3364,3481,4356,4761,5041,6724,6889,7225,7569,7921,8836, %U A046659 10201,10404,11236,11449,12769,13225,13924,15129,17161,18769,19044 %N A046659 Numbers whose sum of divisors and sum of cubes of divisors are relatively prime. %C A046659 It appears that (a) all the numbers are squares, (b) the number of divisors is a power of 3. %C A046659 It can be shown that this is a subset of A028982. %H A046659 Amiram Eldar, <a href="/A046659/b046659.txt">Table of n, a(n) for n = 1..10000</a> %e A046659 k=100 has 9 divisors whose sum is 217 = 7*31 and whose sum of cubes is 1149823 = 19*73*829; gcd(217, 1149823) = 1, so 100 is in the sequence. %t A046659 Select[Range[20000],GCD[DivisorSigma[1,#],DivisorSigma[3,#]]==1&] (* _Harvey P. Dale_, Feb 19 2011 *) %o A046659 (PARI) isok(n) = gcd(sigma(n), sigma(n, 3)) == 1; \\ _Michel Marcus_, May 14 2018 %Y A046659 Cf. A028982, A046679, A046680, A046681, A046683, A046685. %K A046659 nonn %O A046659 1,2 %A A046659 _Labos Elemer_