OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..200
FORMULA
a(n) = A255903(2n,n).
EXAMPLE
a(0) = 1: {}.
a(1) = 2: {{1},{1}}, {{1,1}}.
a(2) = 23: {{1},{1},{1},{2}}, {{1},{1},{2},{2}}, {{1},{2},{2},{2}}, {{1},{1},{1,2}}, {{1},{1},{2,2}}, {{1},{2},{1,1}}, {{1},{2},{1,2}}, {{1},{2},{2,2}}, {{2},{2},{1,1}}, {{2},{2},{1,2}}, {{1,1},{1,2}}, {{1,1},{2,2}}, {{1,2},{1,2}}, {{1,2},{2,2}}, {{1},{1,1,2}}, {{1},{1,2,2}}, {{1},{2,2,2}}, {{2},{1,1,1}}, {{2},{1,1,2}}, {{2},{1,2,2}}, {{1,1,1,2}}, {{1,1,2,2}}, {{1,2,2,2}}.
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Mar 10 2015
STATUS
approved