A229424 - cp's OEIS frontend

A229424 Number of n X 4 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, rows lexicographically nondecreasing, and columns lexicographically nonincreasing.

n	a(n)
1	12
2	55
3	222
4	754
5	2204
6	5700
7	13345
8	28794
9	58053
10	110550
11	200533
12	348855
13	585211
14	950897
15	1502166
16	2314261
17	3486210
18	5146473
19	7459536
20	10633552
21	14929134
22	20669410
23	28251455
24	38159220
25	50978083
26	67411152
27	88297455
28	114632157

[12, 55, 222, 754, 2204, 5700, 13345, 28794, 58053, 110550, 200533, 348855, 585211, 950897, 1502166, 2314261, 3486210, 5146473, 7459536, 10633552, 14929134, 20669410, 28251455, 38159220, 50978083, 67411152, 88297455, 114632157]

cp's OEIS Frontend

A229424 Number of n X 4 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, rows lexicographically nondecreasing, and columns lexicographically nonincreasing.

Table of values

List of values