A242785 - cp's OEIS frontend

A242785 Number of permutations of [n] avoiding the consecutive step pattern given by the binary expansion of n, where 1=up and 0=down.

n	a(n)
0	1
1	1
2	2
3	5
4	21
5	70
6	450
7	4326
8	34944
9	209863
10	1573632
11	21824925
12	302273664
13	2854894485
14	60269056512
15	1207441809209
16	19346879737625
17	252773481889854
18	2918333808555034
19	69792946997645295
20	982945842995115000
21	16085109561896603059
22	402131210857811703926

[1, 1, 2, 5, 21, 70, 450, 4326, 34944, 209863, 1573632, 21824925, 302273664, 2854894485, 60269056512, 1207441809209, 19346879737625, 252773481889854, 2918333808555034, 69792946997645295, 982945842995115000, 16085109561896603059, 402131210857811703926]

cp's OEIS Frontend

A242785 Number of permutations of [n] avoiding the consecutive step pattern given by the binary expansion of n, where 1=up and 0=down.

Table of values

List of values