Number of sequences length n in which neighboring elements differ by 1
11998
In how many sequences of length $n$, the difference between every 2 adjacent elements is $1$ or $-1$?
98850
A positional number system for enumerating fixed-size subsets?
139350
Given two coprime integers, find multiples of them that differ by 1
155372
Find the number of permutations in $S_n$ containing fixed elements in one cycle
50043
Limit of sequence in which each term is defined by the average of preceding two terms
126161
Interesting property of finite integer sequence with sum 1
4221
Determining the number of bit strings of length n that contains no adjacent 0s
93459
Number of permutations of unspecified length
107311
Convergence of a sequence and some of its subsequences
57221
counting the number of elements in a conjugacy class of $S_n$
151466
Series of consecutive numbers (different lengths)
100232
Find equivalent of recurrent sequence $u_1=1$, $u_{n+1}=1+\frac n {u_n}$
153370
Number of different partitions of N
116414
Proving that the difference of the terms of a sequence, multiplied by $n$ converge
134440
An unexpected application of non-trivial combinatorics
74542
Convergence of a sequence whose even and odd subsequences converge
37012
The number of summands $\phi(n)$