OFFSET
3,2
LINKS
EXAMPLE
: a(5) = 6:
: o o o o o o
: / \ / \ /|\ / \ /|\ / | \
: o N o N o N N o o o N N o o N
: / \ /|\ / \ /|\ ( ) /|\ ( ) ( )
: o N o N N o N N N N N N N N N N N N N
: /|\ ( ) ( )
: N N N N N N N
:
MAPLE
b:= proc(n, i, v, k) option remember; `if`(n=0,
`if`(v=0, 1, 0), `if`(i<1 or v<1 or n<v, 0,
`if`(v=n, 1, add(binomial(A(i, k)+j-1, j)*
b(n-i*j, i-1, v-j, k), j=0..min(n/i, v)))))
end:
A:= proc(n, k) option remember; `if`(n<2, n,
add(b(n, n+1-j, j, k), j=2..min(n, k)))
end:
a:= n-> A(n, 3)-A(n, 2):
seq(a(n), n=3..35);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 12 2017
STATUS
approved