A278728 - cp's OEIS frontend

A278728 Number of n X 2 0..3 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly one mistake.

n	a(n)
1	6
2	152
3	1947
4	17352
5	121520
6	712406
7	3633649
8	16547278
9	68531079
10	261693631
11	931194981
12	3113638802
13	9849622993
14	29642927267
15	85271613063
16	235393492799
17	625708778733
18	1606286648601
19	3992748071821
20	9631887926896
21	22595573914587

[6, 152, 1947, 17352, 121520, 712406, 3633649, 16547278, 68531079, 261693631, 931194981, 3113638802, 9849622993, 29642927267, 85271613063, 235393492799, 625708778733, 1606286648601, 3992748071821, 9631887926896, 22595573914587]

cp's OEIS Frontend

A278728 Number of n X 2 0..3 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly one mistake.

Table of values

List of values