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 A046678 #25 May 09 2021 02:17:18 %S A046678 1,2,4,8,9,16,25,36,64,81,100,121,128,144,162,225,256,289,324,400,484, %T A046678 512,529,576,625,729,841,900,1024,1089,1156,1250,1296,1458,1600,1681, %U A046678 1936,2025,2116,2209,2304,2401,2500,2601,2809,3025,3364,3481 %N A046678 Number of divisors of n and sum of divisors of n are relatively prime. %C A046678 It can be shown that this is a subsequence of A028982. %H A046678 Amiram Eldar, <a href="/A046678/b046678.txt">Table of n, a(n) for n = 1..10000</a> %t A046678 Select[Range[3490], CoprimeQ[DivisorSigma[1, #], DivisorSigma[0, #]] &] (* _Jayanta Basu_, Jun 27 2013 *) %o A046678 (PARI) isok(n) = gcd(sigma(n), numdiv(n)) == 1; \\ _Michel Marcus_, Sep 24 2019 %Y A046678 Cf. A000005, A000203, A028982, A046679, A046680, A046681, A046683, A046685. %K A046678 nonn %O A046678 1,2 %A A046678 _Labos Elemer_