cp's OEIS Frontend

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.

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.

Original entry on oeis.org

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, 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, 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
Offset: 0

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Author

Antti Karttunen, Jun 28 2024

Keywords

Crossrefs

Cf. also A374035, A374106.

Programs

  • PARI
    A002110(n) = prod(i=1,n,prime(i));
    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]));
    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]));
    A374116(n) = gcd(A328768(n), A328845(n));