OFFSET
1,5
FORMULA
G.f.: (x*y)/(1-x-x^4-x*y).
EXAMPLE
[1]
[1,1]
[1,2,1]
[1,3,3,1]
[2,4,6,4,1]
[3,7,10,10,5,1]
MATHEMATICA
Table[Sum[Binomial[n - 3*j - 1, k - 1] Binomial[n - k - 3*j, j], {j, 0, (n - k)/3}], {n, 12}, {k, n}] // Flatten (* Michael De Vlieger, Jun 19 2015 *)
PROG
(Maxima) T(n, k):=sum(binomial(n-3*j-1, k-1)*binomial(n-k-3*j, j), j, 0, (n-k)/3);
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Vladimir Kruchinin, Jun 18 2015
STATUS
approved