OFFSET
0,3
EXAMPLE
a(1) = 1: [1,2,1].
a(2) = 3: [1,2,1,2,1], [1,2,1,3,1], [1,2,1,3,2].
CROSSREFS
KEYWORD
nonn
AUTHOR
Joerg Arndt and Alois P. Heinz, Apr 28 2014
STATUS
approved