A252816 - cp's OEIS frontend

A252816 Number of n X 4 nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.

n	a(n)
1	7
2	40
3	187
4	684
5	2078
6	5490
7	13015
8	28299
9	57338
10	109549
11	199168
12	347035
13	582831
14	947837
15	1498290
16	2309416
17	3480225
18	5139158
19	7450681
20	10622926
21	14916484
22	20654460
23	28233905
24	38138745
25	50954332
26	67383747
27	88265990
28	114596197

[7, 40, 187, 684, 2078, 5490, 13015, 28299, 57338, 109549, 199168, 347035, 582831, 947837, 1498290, 2309416, 3480225, 5139158, 7450681, 10622926, 14916484, 20654460, 28233905, 38138745, 50954332, 67383747, 88265990, 114596197]

cp's OEIS Frontend

A252816 Number of n X 4 nonnegative integer arrays with upper left 0 and every value within 2 of its city block distance from the upper left and every value increasing by 0 or 1 with every step right or down.

Table of values

List of values