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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.

A349555 a(n) = Sum_{p<=n, p prime} p^floor(1/gcd(n/p)).

Original entry on oeis.org

0, 1, 3, 4, 6, 7, 11, 16, 15, 12, 18, 25, 29, 34, 35, 40, 42, 55, 59, 72, 69, 66, 78, 97, 96, 87, 98, 93, 101, 122, 130, 159, 148, 143, 150, 157, 161, 178, 183, 192, 198, 229, 239, 270, 275, 258, 282, 325, 322, 323, 310, 315, 329, 378, 367, 374, 361, 352, 382, 433, 441, 470
Offset: 1

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Author

Wesley Ivan Hurt, Nov 21 2021

Keywords

Comments

For each prime number p less than or equal to n, add 1 if p|n, otherwise add p (see example).

Examples

			a(9) = 15; The primes less than or equal to 9 are 2, 3, 5, 7 and only 3|9. We then have, respectively, a(9) = 2 + 1 + 5 + 7 = 15.
		

Crossrefs

Programs

  • Mathematica
    nterms=100;Table[Total[Map[If[Mod[n,#]==0,1,#]&,Prime[Range[PrimePi[n]]]]],{n,nterms}] (* Paolo Xausa, Nov 22 2021 *)

Formula

a(n) = A001221(n) + A066911(n).