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.

A336468 a(n) = A336466(phi(n)), where A336466 is fully multiplicative with a(p) = A000265(p-1) for prime p, with A000265(k) giving the odd part of k.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 5, 11, 1, 3, 1, 1, 1, 3, 1, 1, 1, 1, 3, 7, 1, 1, 1, 1, 1, 1, 1, 5, 1, 5, 1, 3, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 5, 1, 1, 3, 3, 1, 5, 1, 1, 5, 1, 11, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1
Offset: 1

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Author

Antti Karttunen, Jul 22 2020

Keywords

Crossrefs

Programs

  • PARI
    A000265(n) = (n>>valuation(n,2));
    A336468(n) = { my(f=factor(eulerphi(n))); prod(k=1,#f~,A000265(f[k,1]-1)^f[k,2]); };
    \\ Alternatively, as follows, requiring also code from A336466:
    A336468(n) = { my(f=factor(n)); prod(k=1,#f~,A336466(f[k,1]-1) * A336466(f[k,1])^(f[k,2]-1)); };

Formula

a(n) = A336466(A000010(n)).
Multiplicative with a(p^e) = A336466(p-1) * A336466(p)^(e-1).