35345263798
domain: N
Appears in sequences
- Number of 2n-bead black-white strings with n black beads and fundamental period 2n.at n=19A007727
- Number of different ways to select n elements from two sets of n elements under the precondition of choosing at least one element from each set.at n=18A115112
- A115112 with initial term changed from 0 to 1.at n=18A171074
- a(n) = binomial(n, [n/2]) - 2.at n=38A201686
- a(n) = Sum_{k=1..n, gcd(n,k) = 1} binomial(n,k)^2.at n=18A337003