310086

Appears in sequences

• Number of unlabeled 3-element intersecting families (with distinct sets) of an n-element set.at n=20A055485
• Expansion of g.f.: x/((1-x^2)^3 -1+x).at n=13A123888
• a(n) = n-th pi-based antiderivative of 8.at n=30A259169
• Number of 9-compositions of n: matrices with 9 rows of nonnegative integers with positive column sums and total element sum n.at n=5A261801