1239840

Appears in sequences

• a(n) is the number of solutions of the congruence Sum_{k=1..n} x_k == n (mod 2n) where x_k are distinct elements of the set {0,1,...,2n}.at n=6A174668
• Wiener index of the n-permutation star graph.at n=5A284039
• a(n) is the smallest number k >= 1 with exactly n divisors d, for which sigma(k) is divisible by d*sigma(d).at n=38A344103
• Irregular triangle read by rows where T(n,k) is the number of independent sets of size k in the n-folded cube graph.at n=50A355227
• Triangle read by rows: T(n,k) = Sum_{j=0..k} (-1)^j * binomial(k,j) * (1-j)^n.at n=52A389570