26055

Appears in sequences

• Least k such that decimal representation of k*n contains only digits 0 and 9.at n=37A096688
• Number of ways to place zero or more nonadjacent 1,1 2,1 2,2 3,0 3,1 polyhexes in any orientation on a planar nXnXn triangular grid.at n=6A155231
• Number of 0..n arrays x(0..3) of 4 elements without any two consecutive increases or two consecutive decreases.at n=13A200839
• a(n) is the sum of the Wieferich and Wall-Sun-Sun residues of prime(n).at n=43A339639