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 A336645 #17 Jul 29 2020 16:39:20 %S A336645 0,1,1,3,1,6,1,7,8,8,1,11,1,10,9,15,1,17,1,19,11,14,1,18,24,16,25,7,1, %T A336645 18,1,31,15,20,13,35,1,22,17,30,1,30,1,43,41,26,1,47,48,49,21,49,1,42, %U A336645 17,54,23,32,1,57,1,34,61,63,19,54,1,67,27,66,1,71,1,40,73,73,19,66,1,79,80,44,1,77,23,46,33,86,1,88,21 %N A336645 a(n) = n - A326129(n). %C A336645 It seems that A000396 gives all such n for which a(n) = A007913(n). %H A336645 Antti Karttunen, <a href="/A336645/b336645.txt">Table of n, a(n) for n = 1..16384</a> %H A336645 Antti Karttunen, <a href="/A336645/a336645.txt">Data supplement: n, a(n) computed for n = 1..65537</a> %F A336645 a(n) = n - A326129(n) = n - gcd(A326127(n), A326128(n)). %o A336645 (PARI) %o A336645 A326127(n) = (sigma(n)-core(n)-n); %o A336645 A326128(n) = (n-core(n)); %o A336645 A336645(n) = (n-gcd(A326127(n), A326128(n))); %Y A336645 Cf. A000203, A000396, A007913, A326126, A326127, A326128, A326129. %K A336645 nonn %O A336645 1,4 %A A336645 _Antti Karttunen_, Jul 29 2020