login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A274193
Triangular array read by rows: g(n,k) = 1 for n >= 0; g(n,k) = 0 if k > n; g(n,k) = g(n-1,k-1) + g(n-1,3k) for n > 0, k > 1.
6
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 3, 3, 2, 2, 1, 1, 1, 1, 3, 4, 3, 2, 2, 1, 1, 1, 1, 4, 4, 4, 3, 2, 2, 1, 1, 1, 1, 5, 6, 5, 4, 3, 2, 2, 1, 1, 1, 1, 6, 7, 7, 5, 4, 3, 2, 2, 1, 1, 1, 1, 8, 9, 8, 7, 5, 4, 3
OFFSET
0,12
LINKS
EXAMPLE
First 10 rows:
1
1 1
1 1 1
1 1 1 1
1 2 1 1 1
1 2 2 1 1 1
1 2 2 2 1 1 1
1 3 3 2 2 1 1 1
1 3 4 3 2 2 1 1 1
1 4 4 4 3 2 2 1 1 1
MATHEMATICA
g[n_, 0] = g[n, 0] = 1;
g[n_, k_] := g[n, k] = If[k > n, 0, g[n - 1, k - 1] + g[n - 1, 3 k]];
t = Table[g[n, k], {n, 0, 14}, {k, 0, n}]
TableForm[t] (* A274193 array *)
u = Flatten[t] (* A274193 sequence *)
CROSSREFS
Cf. A274194 (row sums), A274195, A274200 (limiting reverse row), A274190, A274196.
Sequence in context: A322812 A259094 A306741 * A238384 A139040 A139147
KEYWORD
nonn,tabl,easy
AUTHOR
Clark Kimberling, Jun 14 2016
STATUS
approved