Matt A and the Online Encyclopedia of Integer Sequences
 

Hi Math People,

The Online Encyclopedia of Integer Sequences is a good reference for integer information. Using a program written by Henry, I lengthened A257138, a list of 13 tuples. I found that the existing 18th entry had one digit too many. I informed the referees and am now waiting for a response. I have contributed to OEIS many times.

[URL]http://oeis.org/A257138[/URL]

Regards,
Matt

[QUOTE=MattcAnderson;407201]Hi Math People,

The Online Encyclopedia of Integer Sequences is a good reference for integer information. Using a program written by Henry, I lengthened A257138, a list of 13 tuples. I found that the existing 18th entry had one digit too many. I informed the referees and am now waiting for a response. I have contributed to OEIS many times.

[URL]http://oeis.org/A257138[/URL]

Regards,
Matt[/QUOTE]

Right - #18 should read 317294052871840123. Length anomaly is much more obvious when the sequence is displayed in list form.

The referees are working on this entry

Hi Math People,

You may see the draft entry for the OEIS entry I am working on now.

[url]https://oeis.org/draft/A257138[/url]

I am still waiting on the referees.

Regards,
Matt

Hi Math People,

A257138 has been corrected.

Regards,
Matt

A034856/
 

Hi Math People,

I was exploring oeis.org. This is the Online Encyclopedia of integer sequences.

[URL="oeis.org/A034856/"]oeis.org/A034856/[/URL]

Many people have double checked this encyclopedia.

I read that for A034856, a(n) reduces to n*(n+3)/2 - 1.

When I work it through, I reach the expression n*(n-1)/2 -1.

Probably I am wrong and the encyclopedia is right.

I assume that binomial(n,k) = n!/(k!(n-k)!).
Can someone else check this expression?

Regards,
Matt

[QUOTE=MattcAnderson;442116][URL="oeis.org/A034856/"]oeis.org/A034856/[/URL]

I read that for A034856, a(n) reduces to n*(n+3)/2 - 1.

When I work it through, I reach the expression n*(n-1)/2 -1.
[/QUOTE]

[CODE]
binomial(n+1, 2) + (n − 1)

n*(n+1) 2*(n−1)
= ------- + -------
2 2

n*n + 1*n + 2*n − 2
= -------------------
2

n*(n+3) − 2
= -----------
2

n*(n+3)
= ------- − 1
2
[/CODE]

Thank you GP2. You are correct.

Regards,
Matt

My contributions to OEIS
 

My best OEIS contribution is A201998. It was part of my "prime producing polynomial" project in 2006.

Matt

oeis.org slash A010882
 

Hi again all,

I thought that it would be fun to share about a OEIS (Online Encyclopedia of Integer Sequences) entry.
This one is a finite and repeating pattern.
Specifically, it starts with one and goes like one, two, three and again one, two, three.

look - [URL="oeis.org/A010882"]A010882[/URL]

Regards,
Matt

My suggestion is, instead of making a new thread for each OEIS sequence that you find interesting, just have a single thread for all of them. I think it would be more interesting.