OFFSET
6,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 6..180
EXAMPLE
a(6) = 6: [1,1,1,1,1,1], [2,2,2,2,2,2], [3,3,3,3,3,3], [4,4,4,4,4,4],[5,5,5,5,5,5], [6,6,6,6,6,6].
a(12) = 2*C(12,2) = 132.
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Aug 28 2013
STATUS
approved