A003688 - cp's OEIS frontend

A003688 a(n) = 3*a(n-1) + a(n-2), with a(1)=1 and a(2)=4.

n	a(n)
1	1
2	4
3	13
4	43
5	142
6	469
7	1549
8	5116
9	16897
10	55807
11	184318
12	608761
13	2010601
14	6640564
15	21932293
16	72437443
17	239244622
18	790171309
19	2609758549
20	8619446956
21	28468099417
22	94023745207
23	310539335038
24	1025641750321
25	3387464586001
26	11188035508324
27	36951571110973

[1, 4, 13, 43, 142, 469, 1549, 5116, 16897, 55807, 184318, 608761, 2010601, 6640564, 21932293, 72437443, 239244622, 790171309, 2609758549, 8619446956, 28468099417, 94023745207, 310539335038, 1025641750321, 3387464586001, 11188035508324, 36951571110973]

cp's OEIS Frontend

A003688 a(n) = 3*a(n-1) + a(n-2), with a(1)=1 and a(2)=4.

Table of values

List of values