A210567 - OEIS

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A210567 as a simple table

n	a(n)
0	1
1	1
2	2
3	4
4	10
5	23
6	63
7	155
8	448
9	1152
10	3452
11	9158
12	28178
13	76539
14	240370
15	665129
16	2123439
17	5964691
18	19302316
19	54898416
20	179696557

[1,1,2,4,10,23,63,155,448,1152,3452,9158,28178, 76539,240370,665129,2123439,5964691,19302316, 54898416,179696557]