A015508 - cp's OEIS frontend

A015508 a(1) = 1, a(n) = Sum_{k=1..n-1} ((7^k - 1)/6)*a(k).

n	a(n)
1	1
2	1
3	9
4	522
5	209322
6	586520244
7	11501075464596
8	1578614616119517768
9	1516734501782248791012168
10	10200952598655696033329019125136
11	480252779391204632593567857157274897424
12	158269444415262012661462389451687149577571916192

[1, 1, 9, 522, 209322, 586520244, 11501075464596, 1578614616119517768, 1516734501782248791012168, 10200952598655696033329019125136, 480252779391204632593567857157274897424, 158269444415262012661462389451687149577571916192]

cp's OEIS Frontend

A015508 a(1) = 1, a(n) = Sum_{k=1..n-1} ((7^k - 1)/6)*a(k).

Table of values

List of values