218700

Appears in sequences

• Numbers of form 3^i*10^j, with i, j >= 0.at n=38A025616
• Triangle read by rows: number of hex trees with n edges and k branches of length 1 (0<=k<=n).at n=56A126321
• If p and q are twin primes then pq + 1 is always divisible by 3, except for (p,q)=(3,5). Sequence gives values of (pq + 1)/3.at n=29A165280
• Totally multiplicative sequence with a(p) = 9*(p+3) for prime p.at n=41A167328
• Triangle read by rows, 3^k*s_3(n, k) where s_m(n, k) are the Stirling-Frobenius cycle numbers of order m; n >= 0, k >= 0.at n=43A225477
• Fixed points of A225546.at n=41A225547
• Number of tilings of a 6 X 6 X n box using 6n bricks of shape 6 X 1 X 1.at n=10A233424
• Numbers m such that Product(1 + p_i) = Product(1 + e_i), where m = Product((p_i)^e_i).at n=30A272858
• Numbers such that the list of exponents of their factorization is a palindromic list of primes.at n=30A322525
• Number of integer grid points on the circle around (0,0) with radius A088959(n).at n=28A365620
• a(n) = 3^(n-3)*(binomial(n,3) + 3*binomial(n,2) + 9*n + 27).at n=9A384198
• Achilles numbers with a primorial squarefree kernel that are not products of primorials.at n=36A386433