The online encyclopaedia of integer sequences

OEIS is, to me, mind-boggling. When you consider that there is literally an infinite number of possible sequences, it’s amazing how often a completely arcane sequence you stumbled upon somewhere is listed in the OEIS.

Also, it’s helped me solve a few project Euler problems (which often involve framing “well-known” problems into novel forms). Brute-force the first few values and more often than not you’ll find the sequence in OEIS, sometimes with a generating function or pointers to the original problem.

Lots of previous discussions: https://hn.algolia.com/?query=integer%20sequences%20points%3...

Did anyone else immediately search 4, 8, 15, 16, 23, 42?