A227615 - cp's OEIS frontend

A227615 Number of bits necessary to represent u(n) in binary, where u is the Lucas-Lehmer sequence: u(0) = 100 (in binary); for n>0, u(n) = u(n-1)^2 - 2.

n	a(n)
0	3
1	4
2	8
3	16
4	31
5	61
6	122
7	244
8	487
9	973
10	1946
11	3892
12	7783
13	15565
14	31130
15	62259
16	124517
17	249033
18	498066
19	996131
20	1992262
21	3984524
22	7969047
23	15938093
24	31876185
25	63752369
26	127504737
27	255009473
28	510018945
29	1020037890
30	2040075780

[3, 4, 8, 16, 31, 61, 122, 244, 487, 973, 1946, 3892, 7783, 15565, 31130, 62259, 124517, 249033, 498066, 996131, 1992262, 3984524, 7969047, 15938093, 31876185, 63752369, 127504737, 255009473, 510018945, 1020037890, 2040075780]

cp's OEIS Frontend

A227615 Number of bits necessary to represent u(n) in binary, where u is the Lucas-Lehmer sequence: u(0) = 100 (in binary); for n>0, u(n) = u(n-1)^2 - 2.

Table of values

List of values