1, 4, 26, 260, 3368, 53744, 1022320, 22522960,
What are these ?

Question

1, 4, 26, 260, 3368, 53744, 1022320, 22522960,
What are these ?

anonymous · Answer

numbers!

anonymous · Answer

true but how obtained ?

hartnn · Answer

related to factorial ?

anonymous · Answer

Combinatorics - everything related

anonymous · Answer

As additional - and simpler challenge :
What are these
1, 2, 5, 14, 42, 132, 429,...

anonymous · Answer

I had to look it up, don't think there will be many getting that one! (the first one)

anonymous · Answer

Do not spoil the second. The first is probably absurdly esoteric

anonymous · Answer

I recognized the second immediately....

anonymous · Answer

Are you a number theorist ?

anonymous · Answer

No, not really but you come across that sequence in some strange places....

anonymous · Answer

I wonder - is there any use of more generalized Fibbonacci - like with different initial conds.

anonymous · Answer

2, 4, 8, 15, 26, 42, 64, Third , and penultimate challenge

anonymous · Answer

anonymous · Answer

Thanks @estudier

anonymous · Answer

Cake numbers - cutting cakes in pieces