A166743 - cp's OEIS frontend

A166743 a(n) = (2^p - p^2 - 1)/6 where p = prime(n).

n	a(n)
3	1
4	13
5	321
6	1337
7	21797
8	87321
9	1398013
10	89478345
11	357913781
12	22906492017
13	366503875645
14	1466015503393
15	23456248058853
16	1501199875789697
17	96076792050570001
18	384307168202281705
19	24595658764946068073

[1, 13, 321, 1337, 21797, 87321, 1398013, 89478345, 357913781, 22906492017, 366503875645, 1466015503393, 23456248058853, 1501199875789697, 96076792050570001, 384307168202281705, 24595658764946068073]

cp's OEIS Frontend

A166743 a(n) = (2^p - p^2 - 1)/6 where p = prime(n).

Table of values

List of values