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 A325317 #9 Apr 22 2019 13:49:55 %S A325317 1,3,4,7,6,12,8,15,13,18,12,28,14,24,24,31,18,23,20,10,32,36,24,60,31, %T A325317 42,32,56,30,72,32,63,48,54,48,67,38,60,56,90,42,96,44,20,46,72,48, %U A325317 124,57,89,72,18,54,96,72,120,80,90,60,40,62,96,104,127,84,144,68,126,96,144,72,187,74,114,124,108,96,168,80 %N A325317 a(n) = A048250(n) XOR A162296(n), where XOR is the bitwise-XOR, A003987. %H A325317 Antti Karttunen, <a href="/A325317/b325317.txt">Table of n, a(n) for n = 1..16384</a> %H A325317 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %H A325317 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a> %F A325317 a(n) = A003987(A048250(n), A162296(n)). %F A325317 a(n) = A000203(n) - 2*A325318(n) = A325316(n) - A325318(n). %t A325317 Array[BitXor @@ Map[Total, {#3, Complement[#2, #3]}] & @@ {#1, #2, Select[#2, SquareFreeQ]} & @@ {#, Divisors[#]} &, 79] (* _Michael De Vlieger_, Apr 21 2019 *) %o A325317 (PARI) %o A325317 A048250(n) = factorback(apply(p -> p+1,factor(n)[,1])); %o A325317 A162296(n) = sumdiv(n, d, d*(1-issquarefree(d))); %o A325317 A325317(n) = bitxor(A048250(n),A162296(n)); %Y A325317 Cf. A000203, A003987, A048250, A162296, A325316, A325318. %K A325317 nonn %O A325317 1,2 %A A325317 _Antti Karttunen_, Apr 21 2019