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.

A305802 Difference in number of prime factors (when counted with multiplicity) between GF(2)[X] (carryless binary) and ordinary factorization: a(n) = A091222(n) - A001222(n).

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 3, 0, 0, 1, 0, 0, 1, 0, -1, 0, 0, 0, 1, 1, 0, 0, 0, 3, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, -1, 3, 0, 1, 0, -1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 2, 0, 0, 3, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, -2, 0, 2, 0, 4, 1, -1, 0, 1, 1, -1, 1, 0, 0, 1, 0, 0, 0, 0, -1, 2, 3, 0, 0, 1
Offset: 1

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Author

Antti Karttunen, Jun 10 2018

Keywords

Crossrefs

Programs

  • PARI
    A091222(n) = vecsum(factor(Pol(binary(n))*Mod(1, 2))[, 2]);
    A305802(n) = (A091222(n) - bigomega(n));

Formula

a(n) = A091222(n) - A001222(n).
For all n, a(A091206(n)) = 0. [Note that zeros occur in other positions as well.]