A054668 - cp's OEIS frontend

A054668 Number of distinct non-extendable sequences X={x(1),x(2),...,x(k)} where x(1)=1, the x(i)'s are distinct elements of {1,...,n} with |x(i)-x(i+1)|=1 or 2, for i=1,2,...,k.

n	a(n)
1	1
2	2
3	4
4	8
5	16
6	30
7	56
8	104
9	192
10	354
11	652
12	1200
13	2208
14	4062
15	7472
16	13744
17	25280
18	46498
19	85524
20	157304
21	289328
22	532158
23	978792
24	1800280
25	3311232
26	6090306
27	11201820
28	20603360
29	37895488
30	69700670
31	128199520
32	235795680
33	433695872
34	797691074
35	1467182628
36	2698569576

[1, 2, 4, 8, 16, 30, 56, 104, 192, 354, 652, 1200, 2208, 4062, 7472, 13744, 25280, 46498, 85524, 157304, 289328, 532158, 978792, 1800280, 3311232, 6090306, 11201820, 20603360, 37895488, 69700670, 128199520, 235795680, 433695872, 797691074, 1467182628, 2698569576]

cp's OEIS Frontend

A054668 Number of distinct non-extendable sequences X={x(1),x(2),...,x(k)} where x(1)=1, the x(i)'s are distinct elements of {1,...,n} with |x(i)-x(i+1)|=1 or 2, for i=1,2,...,k.

Table of values

List of values