On-Line Encyclopedia of Integer Sequences
The On-Line Encyclopedia of Integer Sequences (or OEIS, pronounced "e-i-e-i oh's") is a vast online internet-based database containing an endless supply of incredibly-boring lists of numbers, numbers, more numbers, and even more numbers (if that's at all possible), arranged in, you guessed it... (drum-roll please...) numerical order.
Origins of the database
This immense suppository of mind-numbingly numerical numberation was initially conceived, written, and performed live on-stage in 1965 by Luther (Neil) Sloane, a humble mathematician of Lithuanian descent with way too much time on his hands.
Whilst strolling through the peaceful and serene Lithuanian countryside one fine sunny day, the young innocent Sloane by chance caught a glimpse of the legendary Prime-Number-Shitting Bear (species A000040), doing its — errr, ahem — business adjacent to an unfortunate (and somewhat annoyed) prinne tree. Inspired by the rare sighting, Sloane chased the bear away with several warning shots, collected a rather large quantity of the numerical droppings into a handy burlap sack, and went home to rigorously analyze the precious (and somewhat odious) contents with his most powerful supercomputer (namely, a second-hand ANEMIAC built entirely from spare vacuum tubes and dixie cups). And thus, history itself began to be made.
Contents of the database
Each sequence in the Sloane sequential catalog is sequenced in an entirely logical (i.e., sequential) manner. The very first entry, first discovered by Sloane himself, is indexed by the tag A000000 (formerly A000004), and begins:
which has (as of 2016) been painstakingly calculated to a whopping 500 million billion trillion terms using a powerful algorithm based on Srinivasa Ramanujan's strange and mystical Hinduistic mathematical writings.
As of 2016, the database contains every known (and every previously unknown) sequence of numbers (or integers for the mathematically-inclined snooty folk). In fact, every mathematically-possible sequence (and also the occasional mathematically-impossible sequence) is in there, somewhere, just waiting to be rediscovered, including every conceivable diagonalization of the database itself. Of particular interest is A091967:
0, 2, 1, 0, 2, 3, 0, 6, 6, 4, 44, 1, 180, 42, 16, 1096, 7652, 13781, 8, 24000, 119779, ...
which is the sequence given by the nth term of the nth OEIS sequence. In 1998, Sloane successfully proved (in a stunning dissertation to an otherwise empty CalTech auditorium) that the 91,967th term of A091967 not only exists, but is in fact equal to itself(!). This stunning mathematical breakthrough led immediately to the resolution of all those nasty paradoxes (first gleefully pointed out by Bertrand Russell (c. 1872-1970)) involving the set of all sets that do something-or-other with themselves. In response, the wealthy estate of the British Bertrand Russell Foundation filed suit for patent infringement.
Needless to say, only a finite number of terms for each of the infinitely-many infinite sequences of the database can be explicitly contained in the database itself, partly due to excessive internet bandwidth overload, but mostly due to today's crappy computer screen resolutions.
Utility of the database
The sheer utility of the On-Line Encyclopedia of Integer Sequences cannot be overly underestimated. With just a tiny handful of randomized clicks of the mouse, it is now possible for any homework-laden schoolboy in the world to finally answer the age old question "What is the next number in this sequence?", thereby guaranteeing an automatic A in tomorrow's math class, and subsequently bypassing any presumed need for dreadful remedial math education which would otherwise eat up valuable summer vacation time.
References in small print
- In 2013, an error in the 58,038,150,193,511,253,382th term was accidentally discovered and sheepishly corrected.
- 1999, Russell (deceased) vs Sloane (still alive); case currently under intensive judicial review.