A000225-OEIS公司

A000225号作为一个简单的表

n个	a（n）
0	0
1	1
2	三
三	7
4	15
5	31
6	63
7	127
8	255
9	511
10	1023
11	2047
12	4095
13	8191
14	16383
15	32767
16	65535
17	131071
18	262143
19	524287
20	1048575
21	2097151
22	4194303
23	8388607
24	16777215
25	33554431
26	67108863
27	134217727
28	268435455
29	536870911
30	1073741823
31	2147483647
32	4294967295
33	8589934591

[0,1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535,131071,262143,524287,1048575,2097151,4194303,8388607,16777215,33554431,67108863,134217727,268435455,536870911,1073741823,2147483647,4294967295,8589934591]