A099515 - cp's OEIS frontend

A099515 Row sums of triangle A099514, so that a(n) = Sum_{k=0..n} coefficient of z^k in (1 + z + 2*z^2)^(n-[k/2]), where [k/2] is the integer floor of k/2.

n	a(n)
0	1
1	2
2	5
3	13
4	31
5	78
6	190
7	469
8	1150
9	2825
10	6933
11	17015
12	41754
13	102454
14	251393
15	616826
16	1513453
17	3713389
18	9111087
19	22354678
20	54848638
21	134574493
22	330186518
23	810131889
24	1987705301
25	4876948743
26	11965871650
27	29358946070
28	72033839657

[1, 2, 5, 13, 31, 78, 190, 469, 1150, 2825, 6933, 17015, 41754, 102454, 251393, 616826, 1513453, 3713389, 9111087, 22354678, 54848638, 134574493, 330186518, 810131889, 1987705301, 4876948743, 11965871650, 29358946070, 72033839657]

cp's OEIS Frontend

A099515 Row sums of triangle A099514, so that a(n) = Sum_{k=0..n} coefficient of z^k in (1 + z + 2*z^2)^(n-[k/2]), where [k/2] is the integer floor of k/2.

Table of values

List of values