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 A374116 #6 Jun 28 2024 21:10:51 %S A374116 0,0,1,2,4,1,7,1,12,12,1,1,20,1,1,1,32,1,33,1,4,1,1,1,52,10,1,54,4,1, %T A374116 1,1,80,1,1,4,84,1,1,1,4,1,1,1,4,3,1,1,128,14,5,1,4,1,135,4,4,1,1,1,4, %U A374116 1,1,3,192,6,1,1,4,1,1,1,204,1,1,10,4,2,1,1,16,216,1,1,4,6,1,1,4,1,3,360,4,1,1,24,304,1,7,3,20 %N A374116 a(n) = gcd(A328768(n), A328845(n)), where A328768 is the first primorial based variant and A328845 is the first Fibonacci-based variant of the arithmetic derivative, respectively. %H A374116 Antti Karttunen, <a href="/A374116/b374116.txt">Table of n, a(n) for n = 0..100000</a> %o A374116 (PARI) %o A374116 A002110(n) = prod(i=1,n,prime(i)); %o A374116 A328768(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]*A002110(primepi(f[i,1])-1)/f[i, 1])); %o A374116 A328845(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]*fibonacci(f[i,1])/f[i, 1])); %o A374116 A374116(n) = gcd(A328768(n), A328845(n)); %Y A374116 Cf. A328768, A328845. %Y A374116 Cf. also A374035, A374106. %K A374116 nonn %O A374116 0,4 %A A374116 _Antti Karttunen_, Jun 28 2024