graph6

• https://users.cecs.anu.edu.au/~bdm/data/formats.txt
• (unconventional) base 64 encoding
  • ASCII 63 ? - ASCII 126 ~
  • 6 bits = 1 char
• first char encodes order
  • ?: $n=0$
  • @: $n=1$
  • A: $n=2$
  • ...
• rest chars encode lower triangular matrix
  • in this order

    _ _ _ _
    0 _ _ _
    1 2 _ _
    3 4 5 _
    

  • pad-right with 0

    101010 1111
    ->
    101010 111100
    

• example

  adjMat     order
  0 0 1 1 0  _ _ _ _ _
  0 0 0 1 1  0 _ _ _ _
  1 0 0 0 1  1 2 _ _ _
  1 1 0 0 0  3 4 5 _ _
  0 1 1 0 0  6 7 8 9 _
  
  010110 0110
  010110 011000
  U      W
  
  n=5 -> D
  
  DUW