The Online Encyclopedia of Integer Sequences (and wrestling)

One of the more unique resources for number geeks (like myself) is the OEIS (The Online Encyclopedia of Integer Sequences), created by Neil Sloane.

If you're unfamiliar with the idea, there's a good piece online from Quanta Magazine talking with Sloane about the website.

About a year and half ago, I started working on a chapter for my now-cancelled Kickstarter book called, "Babyface, Heels and Graph Theory". One of things I wondered was how many "traditional" pro-wrestling matches were possible were possible with wrestlers.

I go into greater detail in the PDF (I put the work-in-progress chapter up for free via PayHip yesterday), but when I asked a math professor friend for help, he explained that the sum of the partitions we were calculating was actually the same as a OEIS sequence #A023998.

If you had 8 wrestlers (4 faces, 4 heels) and followed the conditions that I outline (book them in matches where each team is only compromised of babyfaces or heels and everyone wrestles once in either a singles, tag or multi-man tag match), you find there's 131 different "cards" you can put together (before you start accounting for the order on the card). By the time you have a dozen wrestlers, there's well over twenty thousand. And then things start growing even more rapidly.

n	wrestlers	cards
1	2	1
2	4	3
3	6	16
4	8	131
5	10	1,496
6	12	22,482
7	14	426,833
8	16	9,934,563
9	18	277,006,192
10	20	9,085,194,458
11	22	345,322,038,293
12	24	15,024,619,744,202

Links:

http://oeis.org/ - Online Encyclopedia of Integer Sequences
https://www.quantamagazine.org/20150806-neil-sloane-oeis-interview/ - interview with OEIS creator Neil Sloane
https://payhip.com/b/dmpT - a free 10-page from the chapter that was going to be, "Babyfaces, Heels and Graph Theory"