OFFSET
0,2
COMMENTS
An n X n array is bordered if there exists some i,j, with 1 <= i, j < n, such that the first i rows are the same as the last i rows, and the first j columns are the same as the last j columns. Otherwise it is unbordered.
EXAMPLE
For n = 2 the only bordered arrays are the arrays of all 0's and all 1's.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jeffrey Shallit, Oct 01 2016
STATUS
approved