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.

A213731 a(n)=0 if n is in A055938, a(n)=1 if n is in A179016, otherwise (i.e., n is in A213717), a(n)=2.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 2, 1, 0, 0, 0, 1, 1, 0, 2, 1, 0, 0, 2, 1, 0, 2, 1, 0, 0, 0, 0, 1, 1, 0, 2, 1, 0, 0, 2, 1, 0, 2, 1, 0, 0, 0, 1, 2, 0, 1, 2, 0, 0, 1, 2, 0, 2, 1, 0, 0, 0, 0, 0, 1, 1, 0, 2, 1, 0, 0, 2, 1, 0, 2, 1, 0, 0, 0, 1, 2, 0, 1, 2, 0, 0, 1, 2
Offset: 0

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Author

Antti Karttunen, Nov 01 2012

Keywords

Comments

Those natural numbers n for which a(n)=1 belong to the infinite trunk of "Carl White's beanstalk" (see A179016), while the numbers n for which a(n)=0, are the leaves (terminal, dead-end nodes) of the same beanstalk, while those n for which a(n)=2, are non-terminal nodes in its finite tendrils.

Crossrefs

Programs

Formula

a(n) = 2*A079559(n) - A213719(n).