OFFSET
2,1
COMMENTS
Given a cubic n X n X n grid of points, a collection of lines is produced by constructing a line through every pair of points. A222267 gives the count of such lines. a(n) is the total number of points of intersection of these lines, including the original n^3 points.
EXAMPLE
A 2 X 2 X 2 grid of points defines 28 distinct lines which intersect in a total of 15 points (including the original 8 points).
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Clive Tooth, Feb 13 2013
EXTENSIONS
a(6) and a(7) from Clive Tooth, Feb 28 2016
STATUS
approved