[seqfan] The most and least interesting sequences not in OEIS

Keith F. Lynch kfl at KeithLynch.net
Mon Sep 17 05:46:59 CEST 2018

Here is the most interesting sequence I know of that is not in OEIS:

0  -250
1  1400 
2  1706 
3  1949 
4  1958 
5  1961 
6  1973 
7  1983 
8  1987 
9  1989 
10 1997 
11 1999 
12 2002 
13 2011 

The nth term is when pi was first known to have been correctly
calculated to at least 10^n decimal places (or the equivalent
precision in some other notation).  It really shows the astonishing
progress in computer hardware and software.

The 0th term is very uncertain.  Pi has been known to 10^0 place
precision for a very long time, but Archimedes is the first person
known to have *calculated* pi rather than measured it.  I'm not sure
in which decade he did so, but at least I have the century right.

I wonder what the future of this sequence looks like.  When and what
will the last term be?  Or will it keep growing literally forever?

It was rejected from OEIS.  I can understand why, since it isn't math,
even though it's about math.  But then why are A000053 or A007826 there?

And here's the *least* interesting sequence I know of that is not
in OEIS:

17,11,19,24,30, 4,17,27,21,23,
26, 1, 6, 3, 2, 7,11,10,23,28,
27,26,25,30,29,28,27,25, 1,30

The nth term is the day of the month that the nth season of The
Simpsons began (or will begin) on.  On noticing that the upcoming 30th
season is to begin on the 30th (of this month), I wondered if the nth
season had ever begun on the nth of the month before.  The a priori
odds are about 1 - (29/30.5)^29, which is about 0.77, so I figured it
most likely happened exactly once before.  And sure enough, it did.

I have not submitted this sequence, and don't intend to.  I did check,
and sure enough it's not already there.  If someone else wants to
submit it, feel free to take the credit -- or the blame, as the case
may be.

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