A280027 - cp's OEIS frontend

A280027 Fill an infinite square array by following a spiral around the origin; in the central cell enter a(0)=1; thereafter, in the n-th cell, enter the sum of the entries of those earlier cells that can be seen from that cell.

n	a(n)
0	1
1	1
2	2
3	4
4	7
5	13
6	23
7	42
8	76
9	146
10	239
11	441
12	852
13	1389
14	2536
15	4971
16	9832
17	15312
18	27964
19	54801
20	108787
21	169086
22	308758
23	603612
24	1201837
25	2397202
26	3656904
27	6687912
28	13067709
29	25998877
30	51918269
31	79176868
32	144799285
33	282915788
34	562653823
35	1124083053
36	2246758839

[1, 1, 2, 4, 7, 13, 23, 42, 76, 146, 239, 441, 852, 1389, 2536, 4971, 9832, 15312, 27964, 54801, 108787, 169086, 308758, 603612, 1201837, 2397202, 3656904, 6687912, 13067709, 25998877, 51918269, 79176868, 144799285, 282915788, 562653823, 1124083053, 2246758839]

cp's OEIS Frontend

A280027 Fill an infinite square array by following a spiral around the origin; in the central cell enter a(0)=1; thereafter, in the n-th cell, enter the sum of the entries of those earlier cells that can be seen from that cell.

Table of values

List of values