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 A344439 #12 May 26 2021 02:33:51 %S A344439 0,1,1,1,1,4,1,3,2,6,1,6,1,8,7,5,1,11,1,8,9,12,1,14,4,14,7,10,1,22,1, %T A344439 11,13,18,11,15,1,20,15,20,1,30,1,14,17,24,1,26,6,29,19,16,1,34,15,26, %U A344439 21,30,1,36,1,32,21,21,17,46,1,20,25,46,1,37,1,38,33,22,17,54,1,36,20,42,1,48,21,44,31,38,1,62 %N A344439 a(n) = n - A206369(n). %H A344439 Antti Karttunen, <a href="/A344439/b344439.txt">Table of n, a(n) for n = 1..10000</a> %H A344439 Antti Karttunen, <a href="/A344439/a344439.txt">Data supplement: n, a(n) computed for n = 1..65537</a> %F A344439 a(n) = n - A206369(n). %F A344439 a(n) = A344440(n) - A344441(n). %t A344439 Array[# - # DivisorSum[#, LiouvilleLambda[#]/# &] &, 90] (* _Michael De Vlieger_, May 24 2021, after _Enrique Pérez Herrero_ at A206369 *) %o A344439 (PARI) %o A344439 A206369(n) = sumdiv(n, d, eulerphi(n/d) * issquare(d)); \\ From A206369 %o A344439 A344439(n) = (n-A206369(n)); %Y A344439 Cf. A206369, A344440, A344441. %K A344439 nonn %O A344439 1,6 %A A344439 _Antti Karttunen_, May 23 2021