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.

A336316 The number of non-unitary divisors in the conjugated prime factorization of n: a(n) = A048105(A122111(n)).

Original entry on oeis.org

0, 0, 1, 0, 2, 0, 3, 0, 1, 2, 4, 0, 5, 4, 2, 0, 6, 0, 7, 2, 5, 6, 8, 0, 2, 8, 1, 4, 9, 0, 10, 0, 8, 10, 4, 0, 11, 12, 11, 2, 12, 4, 13, 6, 2, 14, 14, 0, 3, 2, 14, 8, 15, 0, 8, 4, 17, 16, 16, 0, 17, 18, 5, 0, 12, 8, 18, 10, 20, 4, 19, 0, 20, 20, 2, 12, 6, 12, 21, 2, 1, 22, 22, 4, 16, 24, 23, 6, 23, 0, 11, 14, 26, 26, 20, 0, 24
Offset: 1

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Author

Antti Karttunen, Jul 18 2020

Keywords

Comments

Equally, the number of divisors in the conjugated prime factorization of n minus the number of its unitary divisors.
Note that A001221(A122111(n)) = A001221(n) for all n.

Crossrefs

Cf. A055932 (the positions of zeros).

Programs

  • PARI
    A336315(n) = if(1==n,n,my(p=apply(primepi,factor(n)[,1]~),m=1+p[1]); for(i=2, #p, m *= (1+p[i]-p[i-1])); (m));
    A336316(n) = (A336315(n)-(2^omega(n)));

Formula

a(n) = A336315(n) - A034444(n) = A000005(A122111(n)) - 2^A001221(n).
a(n) = A048105(A122111(n)).