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.

A350380 Triangle read by rows in which row n lists A014963(d), the exponential of Mangoldt function, for each divisor d of n.

Original entry on oeis.org

1, 1, 2, 1, 3, 1, 2, 2, 1, 5, 1, 2, 3, 1, 1, 7, 1, 2, 2, 2, 1, 3, 3, 1, 2, 5, 1, 1, 11, 1, 2, 3, 2, 1, 1, 1, 13, 1, 2, 7, 1, 1, 3, 5, 1, 1, 2, 2, 2, 2, 1, 17, 1, 2, 3, 1, 3, 1, 1, 19, 1, 2, 2, 5, 1, 1, 1, 3, 7, 1, 1, 2, 11, 1, 1, 23, 1, 2, 3, 2, 1, 2, 1, 1, 1, 5, 5, 1, 2, 13, 1
Offset: 1

Views

Author

Michel Marcus, Dec 28 2021, following a suggestion from Charles Kusniec

Keywords

Examples

			Triangle begins:
  1;
  1, 2;
  1, 3;
  1, 2, 2;
  1, 5;
  1, 2, 3, 1;
  1, 7;
  1, 2, 2, 2;
  1, 3, 3;
  1, 2, 5, 1;
  ...
		

Crossrefs

Cf. A000027 (row products), A140255 (row sums).

Programs

  • Mathematica
    Table[Exp[MangoldtLambda[Divisors[n]]], {n, 1, 26}] // Flatten (* Amiram Eldar, Dec 28 2021 *)
  • PARI
    M(n) = ispower(n, , &n); if(isprime(n), n, 1); \\ A014963
    row(n) = apply(M, divisors(n));

Formula

a(n) = A014963(A027750(n)).