A015448 - cp's OEIS frontend

A015448 a(0) = 1, a(1) = 1, and a(n) = 4*a(n-1) + a(n-2) for n >= 2.

n	a(n)
0	1
1	1
2	5
3	21
4	89
5	377
6	1597
7	6765
8	28657
9	121393
10	514229
11	2178309
12	9227465
13	39088169
14	165580141
15	701408733
16	2971215073
17	12586269025
18	53316291173
19	225851433717
20	956722026041
21	4052739537881
22	17167680177565
23	72723460248141
24	308061521170129
25	1304969544928657
26	5527939700884757

[1, 1, 5, 21, 89, 377, 1597, 6765, 28657, 121393, 514229, 2178309, 9227465, 39088169, 165580141, 701408733, 2971215073, 12586269025, 53316291173, 225851433717, 956722026041, 4052739537881, 17167680177565, 72723460248141, 308061521170129, 1304969544928657, 5527939700884757]

cp's OEIS Frontend

A015448 a(0) = 1, a(1) = 1, and a(n) = 4*a(n-1) + a(n-2) for n >= 2.

Table of values

List of values