2508928

Appears in sequences

• Expansion of g.f. (1 + x - 2*x^2 - x^3)/(1/2 - 2*x^2 + x^4).at n=24A030435
• Number of nonempty subsets of {1,2,...,n} in which exactly 1/6 of the elements are <= n/2.at n=32A047169
• Number of nonempty subsets of {1,2,...,n} in which exactly 1/6 of the elements are <= (n-1)/2.at n=32A047180
• a(n) = (2 + sqrt(2))^n + (2 - sqrt(2))^n.at n=12A056236
• Number of meaningful differential operations of the k-th order on the space R^12.at n=20A129639