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 A324648 #13 Mar 12 2024 09:37:29 %S A324648 1,2,2,4,4,0,6,8,9,2,10,12,12,4,6,16,16,2,18,0,20,16,22,24,25,10,18,0, %T A324648 28,20,30,32,32,34,34,0,36,32,38,8,40,8,42,4,12,36,46,48,49,16,34,16, %U A324648 52,52,38,56,40,26,58,16,60,28,22,64,64,0,66,68,68,4,70,0,72,66,74,12,76,4,78,16,81,82,82,80,64,80,86,0,88 %N A324648 a(n) = n - A318458(n), where A318458(n) is bitwise-AND of n and the sum of proper divisors of n (sigma(n)-n). %H A324648 Antti Karttunen, <a href="/A324648/b324648.txt">Table of n, a(n) for n = 1..16384</a> %H A324648 Antti Karttunen, <a href="/A324648/a324648.txt">Data supplement: n, a(n) computed for n = 1..65537</a> %H A324648 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %H A324648 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %F A324648 a(n) = n - A318458(n). %t A324648 Array[# - BitAnd[#, DivisorSigma[1, #] - #] &, 100] (* _Paolo Xausa_, Mar 12 2024 *) %o A324648 (PARI) %o A324648 A318458(n) = bitand(n,sigma(n)-n); %o A324648 A324648(n) = (n-A318458(n)); %o A324648 (PARI) A324648(n) = (n-bitand(n,sigma(n)-n)); %Y A324648 Cf. A001065, A004198, A318458, A324658, A324649 (positions of zeros). %K A324648 nonn,look %O A324648 1,2 %A A324648 _Antti Karttunen_, Mar 14 2019