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 A379115 #11 Dec 16 2024 08:47:11 %S A379115 0,0,1,2,4,0,2,3,2,2,0,4,0,3,3,0,2,2,3,1,0,3,4,2,2,0,4,4,0,4,0,4,0,4, %T A379115 1,0,4,2,1,0,0,1,2,2,0,0,2,3,3,2,0,0,4,3,0,0,3,1,2,1,0,1,4,1,2,0,1,3, %U A379115 1,2,0,4,4,3,1,0,0,1,4,1,0,1,3,2,1,0,2,0,4,4,0,0,0,4,3,0,4,2,3,3,0,1,1,2,0,0 %N A379115 a(n) = A328845(n) mod 5, where A328845 is the first Fibonacci based variant of arithmetic derivative. %H A379115 Antti Karttunen, <a href="/A379115/b379115.txt">Table of n, a(n) for n = 0..81839</a> %F A379115 a(n) = A010874(A328845(n)) = A010874(A374125(n)). %t A379115 A379115[n_] := If[n <= 1, 0, Mod[n*Total[MapApply[#2*Fibonacci[#]/# &, FactorInteger[n]]], 5]]; %t A379115 Array[A379115, 100, 0] (* _Paolo Xausa_, Dec 16 2024 *) %o A379115 (PARI) A379115(n) = if(n<=1, 0, my(f=factor(n)); (n*sum(i=1, #f~, f[i, 2]*fibonacci(f[i,1])/f[i, 1]))%5); %Y A379115 Cf. A010874, A328845, A374125, A374205, A379116 (positions of 0's), A379117 (their characteristic function). %K A379115 nonn %O A379115 0,4 %A A379115 _Antti Karttunen_, Dec 15 2024