42006

Appears in sequences

• Numbers k > 1 such that, in base 5, k and k^2 contain the same digits in the same proportion.at n=11A061659
• Number of (n+2) X 4 binary arrays with every 3 X 3 subblock commuting with each horizontal and vertical neighbor 3 X 3 subblock.at n=22A190026
• Start with a Koch snowflake tile, and repeatedly append along the tiles of the previous step tiles scaled by a factor of sqrt(1/3) and rotated by 90 degrees that do not overlap with any prior tile and of which one third of the perimeter matches one sixth of the perimeter of adjacent prior tiles; a(n) gives the number of tiles appended at n-th step.at n=14A330844