OFFSET
6,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 6..650
EXAMPLE
a(8) = 3: .o-o o o. .o-o o o. .o o o o.
.|/ . .| . .| | .
.o o o o. .o o o o. .o o o o.
MAPLE
with(numtheory):
b:= proc(n) option remember; local d, j; `if`(n<=1, n,
(add(add(d*b(d), d=divisors(j)) *b(n-j), j=1..n-1))/(n-1))
end:
g:= proc(n) option remember; local k; `if`(n>2, 1, 0)+ b(n)-
(add(b(k)*b(n-k), k=0..n) -`if`(irem(n, 2)=0, b(n/2), 0))/2
end:
p:= proc(n, i, t) option remember; `if`(n<t, 0, `if`(n=t, 1,
`if`(min(i, t)<1, 0, add(binomial(g(i)+j-1, j)*
p(n-i*j, i-1, t-j), j=0..min(n/i, t)))))
end:
a:= n-> p(n, n, 6):
seq(a(n), n=6..40);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Aug 29 2012
STATUS
approved