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 A373976 #7 Jun 24 2024 17:10:07 %S A373976 0,0,0,0,0,1,0,1,0,1,0,2,0,0,-1,1,0,0,0,1,0,1,0,2,0,0,1,2,0,1,0,3,0,1, %T A373976 -1,2,0,0,-2,3,0,0,0,1,2,0,0,4,0,0,-1,2,0,3,-2,3,0,1,0,1,0,0,2,3,-1, %U A373976 -1,0,1,0,1,0,2,0,0,2,2,-1,0,0,4,1,1,0,2,0,-1,-3,3,0,3,-1,0,0,0,-2,5,0,-1,2,2,0 %N A373976 a(n) = A001222(n) - A001222(A001414(n)), where A001222 is bigomega, the number of prime factors with multiplicity, and A001414 is sopfr, sum of prime factors with multiplicity. a(1) = 0 by convention. %H A373976 Antti Karttunen, <a href="/A373976/b373976.txt">Table of n, a(n) for n = 1..65537</a> %F A373976 a(n) = A001222(n) - A342956(n). %o A373976 (PARI) %o A373976 A001414(n) = ((n=factor(n))[, 1]~*n[, 2]); \\ From A001414. %o A373976 A373976(n) = if(1==n, 0, bigomega(n)-bigomega(A001414(n))); %Y A373976 Cf. A001222, A001414, A342956. %Y A373976 Cf. also A045835. %K A373976 sign %O A373976 1,12 %A A373976 _Antti Karttunen_, Jun 24 2024