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.

A140694 a(n) = A014963(n) * A063659(n).

Original entry on oeis.org

1, 4, 9, 6, 25, 6, 49, 12, 24, 10, 121, 9, 169, 14, 15, 24, 289, 16, 361, 15, 21, 22, 529, 18, 120, 26, 72, 21, 841, 30, 961, 48, 33, 34, 35, 24, 1369, 38, 39, 30, 1681, 42, 1849, 33, 40, 46, 2209, 36, 336, 48, 51, 39, 2809, 48, 55, 42, 57, 58, 3481, 45, 3721
Offset: 1

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Author

Gary W. Adamson and Mats Granvik, May 23 2008

Keywords

Comments

A140579 as an infinite lower triangular matrix * A063659 as a vector.

Examples

			a(4) = A014963(4) * A063659(4) = 2 * 3  = 6.
		

Crossrefs

Programs

  • Mathematica
    f[p_, e_] := If[e == 1, p, p^e - p^(e - 2)]; a[n_] := Exp[MangoldtLambda[n]] * Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, May 18 2025 *)

Formula

a(n) = n^2 iff n is prime.
a(n) = n iff mu(n) = 1.

Extensions

More terms from Amiram Eldar, May 18 2025