Eureka Sequences - Numberphile

OEIS founder Neil Sloane with more sequences to ponder - of course!
More links & stuff in full description below ↓↓↓

NUMBERPHILE

Videos by Brady Haran
Animation by Pete McPartlan

[JoeTaber]

The animation of Neil instantly tossing Brady's "primes+8" sequence in the dumpster at the back of OEIS Headquarters is inexplicably hilarious 😂

[copperfield]

0:21 now I want a look at the dangerous sequence section XD

[zlodevil]

I love how there’s a square root button in the elevator at 0:12

[aL_]

man the animations in this one are next level :)

[rmsgrey]

Back when the Wu riddle forums were more active (maybe 20 years ago) we distinguished between "riddles" and "puzzles" by analogy with the P vs NP problem - puzzles offer places to start, and strategies to solve them, so that even if you don't know anything about the answer, you can at least feel like you make progress toward finding it; riddles, like NP-hard problems, are very hard (maybe even impossible) to solve by working forwards, but if you can guess the answer, it's easy to check that it's right.

Using this taxonomy, both of these sequences fall on the "riddle" end of the spectrum.

[Playmaker]

Moral of the video: Always checking the bathrooms before doing an interview, because there may be 10 persons like you in there

[unvergebeneid]

Brady seems determined to make a video on every single sequence in the OEIS. And I'm totally okay with that.

[ryanoftinellb]

I guessed the first one from Neil's "10, no, 11, no, 12, yes" at 0:49, because it's very similar to how I remember the primes.

[donotworried]

Beautiful opening animation! Kudos to the animator for capturing the tone of the video 👏👏

[MoosesValley]

The cartoon animations of Neil entering the OEIS, taking the elevator, walking down the halls, etc are all top notch. If there was a cartoon series about Neil investigating mysteries, strange happenings, missing people, etc and using maths (prime numbers, fibonacci, Pi, e, ...) to help crack clues and solve the cases ... I'd certainly watch. :)

[TheDmviper]

I feel really proud that I figured out the 5, 8, 12, 18, 24, ... sequence as soon as it was given. But I suppose I was primed to spot it.

[MCRuCr]

This is a nice example of occhams razor. For each of these puzzles, indefinitely many solutions exist, but we should consider THAT solution as the "right" one, which is easiest (shortest) to explain.

[EarlOfWarwick]

Lo-fi Neil Sloane OEIS chill beats to study and relax to

[Reggiamoto]

Came up with a different solution for the second sequence: Add the last two terms (like Fibonacci), then subtract (n-2)!.
So you'd add 5+8, then subtract 1!, which is 12.
8+12-2!=18
12+18-3!=24
It would then continue like this:
18+24-4!=18
24+18-5!=-78

[HonkeyKongLive]

I would buy a DVD of animations like this with Neil talking about sequences. This is not a joke. Cash in hand.

[StanSays]

I like the way he enthusiastically says the numbers

[SolinoOruki]

He's one of my favorite. And the animations makes it even better

[LuigiElettrico]

Wow. The animations leveled up to the 3rd dimension :D

[pooyataleb]

I actually solved the second one based on the fact that we were already on the subject of primes but solid advice regardless

[michaelking]

Hey!! I just wanted to say, I’m a maths hobbyist and I have used the OEIS many times to solve problems!