2581112

Appears in sequences

• a(n) = (1/(2n)) * Sum_{d|n} phi(d) * 2^(2n/d) + (2^((n-4)/2), if n is even).at n=10A058880
• An intermediate sequence for nonisomorphic circulant self-complementary undirected p^2-graphs, indexed by odd primes p.at n=14A061848
• Number of subsets of {1,2,...,n} which sum to 0 modulo n.at n=25A063776
• Number of subsets of {1,2,3,...,n} that sum to 0 mod 13.at n=25A068034
• Number of frieze patterns of length n under a certain group (see Pisanski et al. for precise definition).at n=13A123045
• Number of solutions to 1 +- 3 +- 5 +- ... +- (2*n-1) == 0 mod n.at n=25A300218
• a(n) = ceiling((2^n+n-1)/n).at n=25A373895