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.

A358669 Pointwise product of the arithmetic derivative and the primorial base exp-function.

Original entry on oeis.org

0, 0, 3, 6, 36, 18, 25, 10, 180, 180, 315, 90, 400, 50, 675, 1200, 7200, 450, 2625, 250, 9000, 7500, 14625, 2250, 27500, 12500, 28125, 101250, 180000, 11250, 217, 14, 1680, 588, 1197, 1512, 2100, 70, 2205, 3360, 21420, 630, 7175, 350, 25200, 40950, 39375, 3150, 98000, 24500, 118125, 105000, 441000
Offset: 0

Views

Author

Antti Karttunen, Dec 05 2022

Keywords

Crossrefs

Cf. A003415, A059841, A121262, A152822, A276086, A327858, A353558, A358680, A358765 (= a(n) mod 60), A359423, A359603 [Dirichlet inverse of 1+a(n)].
Cf. A016825 (positions of odd terms), A042965 (of even terms), A235992 (of multiples of 4), A067019 (of terms of the form 4k+2), A358748 (of the form 4k+1), A358749 (of the form 4k+3).

Programs

  • PARI
    A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
    A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
    A358669(n) = (A003415(n)*A276086(n));

Formula

a(n) = A003415(n) * A276086(n).
From Antti Karttunen, Jan 09 2023: (Start)
a(n) = A327858(n) * A359423(n).
For all n >= 0, A059841(a(n)) = A152822(n).
For all n >= 1, 1-A152822(a(n)) = A353558(n).
For all n >= 0, A121262(a(n)) = A358680(n).
(End)