# [seqfan] Re: What is the difference between A000610 and A001320?

Joerg Arndt arndt at jjj.de
Wed Apr 14 14:29:59 CEST 2010

```* Jonathan Post <jvospost3 at gmail.com> [Apr 14. 2010 13:03]:
> What is the difference between A000610 and A001320?
>
> The have different values, but the same name:   Number of
> self-complementary Boolean functions of n variables.
>
> They have the same author, and were extended on the same date by the
> same person.
>
> A001320 has Maple code;

Somewhat simplified, as pari/gp code:

A001320(n)=(2^(2^n)) * sum(j=0,n,1/2^(j+1))  \\ pull out silly 'fermat(n)'
A001320(n)=(2^(2^n)) * (2^(n+1)-1)/(2^(n+1)) \\ eval sum
A001320(n)=(2^(2^n - n - 1)) * (2^(n+1)-1)   \\ combine exponents

I cannot verify the correctness of the code given
(beyond the terms given).

> A000610 does not, nor a formula given.
>
> So what is the relationship?  One right and one wrong, or different
> definitions based on some detail not shown?
>
> Thank you,
>
> Prof. Jonathan Vos Post
>
>
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>
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```