OFFSET
5,3
EXAMPLE
a(6) = 1: 111111.
a(7) = 4: 111121, 111211, 112111, 121111.
a(8) = 13: 111131, 111221, 111311, 112121, 112211, 113111, 121121, 121211, 122111, 131111, 211112, 1111112, 2111111.
a(9) = 34: 111141, 111231, 111321, 111411, 112131, 112221, 112311, 113121, 113211, 114111, 121131, 121221, 121311, 122121, 122211, 123111, 131121, 131211, 132111, 141111, 211122, 211212, 212112, 221112, 1111113, 1111212, 1112112, 1121112, 1211112, 2111121, 2111211, 2112111, 2121111, 3111111.
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 14 2015
STATUS
approved