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.

A351368 a(n) = Sum_{p|n, p prime} prime(p).

Original entry on oeis.org

0, 3, 5, 3, 11, 8, 17, 3, 5, 14, 31, 8, 41, 20, 16, 3, 59, 8, 67, 14, 22, 34, 83, 8, 11, 44, 5, 20, 109, 19, 127, 3, 36, 62, 28, 8, 157, 70, 46, 14, 179, 25, 191, 34, 16, 86, 211, 8, 17, 14, 64, 44, 241, 8, 42, 20, 72, 112, 277, 19, 283, 130, 22, 3, 52, 39, 331, 62, 88
Offset: 1

Views

Author

Wesley Ivan Hurt, Feb 08 2022

Keywords

Comments

Inverse Möbius transform of prime(n) * c(n), where c(n) is the characteristic function of primes (A010051). - Wesley Ivan Hurt, Jun 29 2024

Examples

			a(6) = 8; a(6) = Sum_{p|6, p prime} prime(p) = prime(2) + prime(3) = 3 + 5 = 8.
		

Crossrefs

Programs

  • Mathematica
    Table[DivisorSum[n, Prime[#] &, PrimeQ[#] &], {n, 100}] (* Wesley Ivan Hurt, Jun 29 2024 *)

Formula

From Wesley Ivan Hurt, Jun 29 2024: (Start)
a(n) = Sum_{d|n} prime(d) * c(d), where c = A010051.
a(p^k) = prime(p), for prime p and k >= 1. (End)