OFFSET
9,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 9..1000
FORMULA
G.f.: x^9/((x-1)*(3*x-1)*(2*x+1)*(2*x-1)*(3*x+1)*(4*x-1)*(x+1)* (12*x^2-1)*(6*x^2-1)*(20*x^2-1)*(2*x^2-1)).
EXAMPLE
a(9) = 1: 1|2|3|4|5|6|7|8|9.
a(10) = 4: 1|2(10)|3|4|5|6|7|8|9, 1|2|3|4(10)|5|6|7|8|9, 1|2|3|4|5|6(10)|7|8|9, 1|2|3|4|5|6|7|8(10)|9.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Jul 09 2016
STATUS
approved