A233776 - cp's OEIS frontend

A233776 Number of grid points that are covered on the semi-infinite hexagonal grid after n-th stage in a cellular automaton in which the toothpicks are connected by their endpoints but the toothpicks placed in northwest or northeast direction are prohibited, starting with a(0) = 1.

n	a(n)
0	1
1	2
2	4
3	6
4	9
5	11
6	15
7	19
8	24
9	26
10	30
11	34
12	40
13	44
14	52
15	60
16	69
17	71
18	75
19	79
20	85
21	89
22	97
23	105
24	115
25	119
26	127
27	135
28	147
29	155
30	171
31	187
32	204
33	206
34	210
35	214
36	220
37	224
38	232
39	240
40	250
41	254
42	262
43	270
44	282
45	290
46	306
47	322
48	340
49	344
50	352
51	360
52	372
53	380
54	396
55	412
56	432
57	440
58	456
59	472
60	496

[1, 2, 4, 6, 9, 11, 15, 19, 24, 26, 30, 34, 40, 44, 52, 60, 69, 71, 75, 79, 85, 89, 97, 105, 115, 119, 127, 135, 147, 155, 171, 187, 204, 206, 210, 214, 220, 224, 232, 240, 250, 254, 262, 270, 282, 290, 306, 322, 340, 344, 352, 360, 372, 380, 396, 412, 432, 440, 456, 472, 496]

cp's OEIS Frontend

A233776 Number of grid points that are covered on the semi-infinite hexagonal grid after n-th stage in a cellular automaton in which the toothpicks are connected by their endpoints but the toothpicks placed in northwest or northeast direction are prohibited, starting with a(0) = 1.

Table of values

List of values

n	a(n)
0	1
1	2
2	4
3	6
4	9
5	11
6	15
7	19
8	24
9	26
10	30
11	34
12	40
13	44
14	52
15	60
16	69
17	71
18	75
19	79
20	85
21	89
22	97
23	105
24	115
25	119
26	127
27	135
28	147
29	155
30	171
31	187
32	204
33	206
34	210
35	214
36	220
37	224
38	232
39	240
40	250
41	254
42	262
43	270
44	282
45	290
46	306
47	322
48	340
49	344
50	352
51	360
52	372
53	380
54	396
55	412
56	432
57	440
58	456
59	472
60	496

n	a(n)
0	1
1	2
2	4
3	6
4	9
5	11
6	15
7	19
8	24
9	26
10	30
11	34
12	40
13	44
14	52
15	60
16	69
17	71
18	75
19	79
20	85
21	89
22	97
23	105
24	115
25	119
26	127
27	135
28	147
29	155
30	171
31	187
32	204
33	206
34	210
35	214
36	220
37	224
38	232
39	240
40	250
41	254
42	262
43	270
44	282
45	290
46	306
47	322
48	340
49	344
50	352
51	360
52	372
53	380
54	396
55	412
56	432
57	440
58	456
59	472
60	496

n	a(n)
0	1
1	2
2	4
3	6
4	9
5	11
6	15
7	19
8	24
9	26
10	30
11	34
12	40
13	44
14	52
15	60
16	69
17	71
18	75
19	79
20	85
21	89
22	97
23	105
24	115
25	119
26	127
27	135
28	147
29	155
30	171
31	187
32	204
33	206
34	210
35	214
36	220
37	224
38	232
39	240
40	250
41	254
42	262
43	270
44	282
45	290
46	306
47	322
48	340
49	344
50	352
51	360
52	372
53	380
54	396
55	412
56	432
57	440
58	456
59	472
60	496