275622

Appears in sequences

• Number of 3-covers of an unlabeled n-set.at n=27A055195
• Solution of the complementary equation a(n) = 2*a(n-1) - a(n-3) + b(n-1), where a(0) = 1, a(1) = 3, a(2) = 5, b(0) = 2, b(1) = 4, b(2) = 6, and (a(n)) and (b(n)) are increasing complementary sequences.at n=21A295614