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A289962 as a simple table

na(n)
01
11
23
315
431
515
631
763
8127
963
10127
11255
12511
131023
142047
154095
168191
1715359
1830719
1965535
20131071
21245759
22491519
231048575
242097151
253604479
267208959
2716777215
2833554431
2958458111
30116916223
31176160767
32352321535
33301203455
34602406911
35131071999

[1,1,3,15,31,15,31,63,127,63,127,255,511,1023,
 2047,4095,8191,15359,30719,65535,131071,245759,
 491519,1048575,2097151,3604479,7208959,16777215,
 33554431,58458111,116916223,176160767,352321535,
 301203455,602406911,131071999]