47185920

Appears in sequences

• Expansion of (1 + x - 2*x^2)/(1 - 2*x)^2.at n=21A052951
• a(n) = Product_{i=2..n} phi(i)/bigomega(i).at n=16A066988
• Number of subsets of {1,.., n} containing exactly two primes.at n=29A089822
• Number of subsets of {1,.., n} containing no twin prime pairs.at n=26A089827
• Row sums of triangle A094280.at n=23A094283
• a(n) = (n^3 - n^2)*8^n.at n=5A128991
• Number of directed Hamiltonian paths in the 2n-crossed prism graph.at n=13A137885