25534

Appears in sequences

• Number of solutions to c(1)*prime(2) +...+ c(n)*prime(n+1) = 0, where c(i) = +-1 for i > 1, c(1) = 1.at n=23A022897
• a(n) is the number of times that sums 3 +- 5 +- 7 +- 11 +- ... +- prime(2n+1) of the first 2n odd primes is zero. There are 2^(2n-1) choices for the sign patterns.at n=11A083309
• a(n) = 2*prime(n)^2 - 4.at n=29A153480
• Number of tatami tilings of a 7 X n grid (with monomers allowed).at n=13A192093
• Number of strings of length n in {2,3}* for which at least one of tail(2 S) > tail(S) and tail(3 S) > tail(S) holds.at n=33A217437
• a(n) = floor(M(g(n-1)+1,..,g(n))), where M = harmonic mean and g(n) = n*(n + 1)*(n + 2)*(n + 3)/24.at n=26A227018
• Expansion of 1/2 * (((1 + 4*x)/(1 - 4*x))^(1/4) - 1).at n=10A305608
• Number of unlabeled semi-binary rooted trees with n nodes in which the non-leaf branches directly under any given node are all equal.at n=21A320271