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 A054022 #10 Oct 27 2023 22:00:46 %S A054022 1,2,3,5,7,9,11,13,15,17,19,23,27,29,31,32,35,36,37,39,41,43,47,50,51, %T A054022 53,55,59,61,67,71,73,75,79,83,87,89,91,95,97,98,101,103,107,109,111, %U A054022 113,115,119,123,127,131,135,137,139,143,149,151,155,157,159,162,163 %N A054022 Chowla function of n is divisible by the number of divisors of n. %C A054022 Chowla's function (A048050) = sum of divisors of n except 1 and n. %H A054022 Harvey P. Dale, <a href="/A054022/b054022.txt">Table of n, a(n) for n = 1..1000</a> %p A054022 with(numtheory): %p A054022 [seq(`if`((sigma(i)-i-1) mod tau(i)=0,i,print( )),i=1..1000)]; %t A054022 Select[Range[200],Divisible[DivisorSigma[1,#]-1-#,DivisorSigma[0,#]]&] (* _Harvey P. Dale_, Mar 11 2012 *) %Y A054022 Complement is A054023 Cf. A000005, A048050, A054014. %K A054022 nonn %O A054022 1,2 %A A054022 _Asher Auel_, Jan 19 2000