OFFSET
0,6
EXAMPLE
a(3) = 1: 111.
a(4) = 1: 121.
a(5) = 4: 131, 212, 1112, 2111.
a(6) = 6: 141, 222, 1113, 1212, 2121, 3111.
a(7) = 13: 151, 232, 313, 1114, 1213, 1222, 1312, 2131, 2221, 3121, 4111, 11122, 22111.
a(8) = 23: 161, 242, 323, 1115, 1214, 1232, 1313, 1412, 2123, 2141, 2321, 3131, 3212, 4121, 5111, 11123, 11132, 11222, 21113, 22211, 23111, 31112, 32111.
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 14 2015
STATUS
approved