A056640 - cp's OEIS frontend

A056640 At stage 1, start with a unit square. At each successive stage add 4*(n-1) new squares around outside with edge-to-edge contacts. Sequence gives number of squares (regardless of size) at n-th stage.

n	a(n)
1	1
2	5
3	18
4	42
5	83
6	143
7	228
8	340
9	485
10	665
11	886
12	1150
13	1463
14	1827
15	2248
16	2728
17	3273
18	3885
19	4570
20	5330
21	6171
22	7095
23	8108
24	9212
25	10413
26	11713
27	13118
28	14630
29	16255
30	17995
31	19856
32	21840
33	23953
34	26197
35	28578
36	31098
37	33763
38	36575
39	39540
40	42660
41	45941
42	49385
43	52998

[1, 5, 18, 42, 83, 143, 228, 340, 485, 665, 886, 1150, 1463, 1827, 2248, 2728, 3273, 3885, 4570, 5330, 6171, 7095, 8108, 9212, 10413, 11713, 13118, 14630, 16255, 17995, 19856, 21840, 23953, 26197, 28578, 31098, 33763, 36575, 39540, 42660, 45941, 49385, 52998]

cp's OEIS Frontend

A056640 At stage 1, start with a unit square. At each successive stage add 4*(n-1) new squares around outside with edge-to-edge contacts. Sequence gives number of squares (regardless of size) at n-th stage.

Table of values

List of values