A099513 - cp's OEIS frontend

A099513 Row sums of triangle A099512, so that a(n) = Sum_{k=0..n} coefficient of z^k in (1 + 3*z + z^2)^(n-[k/2]), where [k/2] is the integer floor of k/2.

n	a(n)
0	1
1	4
2	8
3	27
4	89
5	257
6	784
7	2421
8	7336
9	22324
10	68147
11	207549
12	632177
13	1926608
14	5870089
15	17884476
16	54493120
17	166034731
18	505883825
19	1541369745
20	4696373312
21	14309268413
22	43598614528
23	132839740908
24	404746601923
25	1233213978037

[1, 4, 8, 27, 89, 257, 784, 2421, 7336, 22324, 68147, 207549, 632177, 1926608, 5870089, 17884476, 54493120, 166034731, 505883825, 1541369745, 4696373312, 14309268413, 43598614528, 132839740908, 404746601923, 1233213978037]

cp's OEIS Frontend

A099513 Row sums of triangle A099512, so that a(n) = Sum_{k=0..n} coefficient of z^k in (1 + 3*z + z^2)^(n-[k/2]), where [k/2] is the integer floor of k/2.

Table of values

List of values