912384

Appears in sequences

• Theta series of laminated lattice LAMBDA_10.at n=17A006909
• a(n)=(1/2)*T(2n+1,n+1), where T is given by A048113.at n=11A048119
• a(n) = phi(binomial(2n, n)).at n=11A066973
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 0), (0, 0, 1), (0, 1, -1), (1, -1, -1)}.at n=15A148018
• Number of elements of order n in the simple unitary group U2(5).at n=4A284984
• Number of subsets of {2...n} containing no element whose prime indices all belong to the subset.at n=23A324739
• a(n) is the smallest number m such that gcd(m, tau(m), sigma(m), pod(m)) = n where tau(k) is the number of divisors of k (A000005), sigma(k) is the sum of divisors of k (A000203) and pod(k) is the product of divisors of k (A007955).at n=21A337324
• a(n) is the smallest number m such that gcd(tau(m), sigma(m), pod(m)) = n where tau(k) is the number of divisors of k (A000005), sigma(k) is the sum of divisors of k (A000203) and pod(k) is the product of divisors of k (A007955).at n=21A337325
• a(n) = Sum_{1 <= x_1 <= x_2 <= x_3 <= x_4 <= x_5 <= x_6 <= n} gcd(x_1, x_2, x_3 , x_4, x_5, x_6, n).at n=26A343520