18227

Appears in sequences

• a(0) = 1, a(n) = 25*n^2 + 2 for n > 0.at n=27A010015
• Numbers k that divide the (right) concatenation of all numbers <= k written in base 23 (most significant digit on left).at n=23A029468
• a(n) = n^3 - 2*n^2 + 2.at n=26A100109
• Number of triangles that can be built from rods with lengths 1,2,...,n by using and concatenating not necessarily all rods.at n=13A160456
• Number of (n+2)X(3+2) 0..2 arrays with every row, column, diagonal or antidiagonal in each 3X3 subblock summing to a prime.at n=4A251814
• Number of (n+2)X(5+2) 0..2 arrays with every row, column, diagonal or antidiagonal in each 3X3 subblock summing to a prime.at n=2A251816
• T(n,k)=Number of (n+2)X(k+2) 0..2 arrays with every row, column, diagonal or antidiagonal in each 3X3 subblock summing to a prime.at n=23A251819
• T(n,k)=Number of (n+2)X(k+2) 0..2 arrays with every row, column, diagonal or antidiagonal in each 3X3 subblock summing to a prime.at n=25A251819
• Composite numbers k such that phi(k)^phi(k) == k + 1 (mod k^2).at n=1A319370
• Numbers that are the sum of eight fourth powers in eight or more ways.at n=23A345583
• Numbers that are the sum of eight fourth powers in nine or more ways.at n=7A345584
• Numbers that are the sum of eight fourth powers in exactly nine ways.at n=5A345841
• Semiprimes of the form k^2 + 2.at n=37A360739