A162547 - cp's OEIS frontend

A162547 Somos-4 variant: if n!=4k+1, then a(n) = (4a(n-1)a(n-3) - 4*a(n-2)^2) / a(n-4), otherwise a(n) = 0, with a(-2) = a(-1) = a(0) = 1.

n	a(n)
0	1
1	0
2	-4
3	-16
4	-64
5	0
6	4096
7	65536
8	1048576
9	0
10	-1073741824
11	-68719476736
12	-4398046511104
13	0
14	72057594037927936
15	18446744073709551616
16	4722366482869645213696
17	0
18	-1237940039285380274899124224
19	-1267650600228229401496703205376
20	-1298074214633706907132624082305024
21	0

[1, 0, -4, -16, -64, 0, 4096, 65536, 1048576, 0, -1073741824, -68719476736, -4398046511104, 0, 72057594037927936, 18446744073709551616, 4722366482869645213696, 0, -1237940039285380274899124224, -1267650600228229401496703205376, -1298074214633706907132624082305024, 0]

cp's OEIS Frontend

A162547 Somos-4 variant: if n!=4k+1, then a(n) = (4a(n-1)a(n-3) - 4*a(n-2)^2) / a(n-4), otherwise a(n) = 0, with a(-2) = a(-1) = a(0) = 1.

Table of values

List of values

cp's OEIS Frontend

A162547 Somos-4 variant: if n!=4k+1, then a(n) = (4*a(n-1)*a(n-3) - 4*a(n-2)^2) / a(n-4), otherwise a(n) = 0, with a(-2) = a(-1) = a(0) = 1.

Table of values

List of values

A162547 Somos-4 variant: if n!=4k+1, then a(n) = (4a(n-1)a(n-3) - 4*a(n-2)^2) / a(n-4), otherwise a(n) = 0, with a(-2) = a(-1) = a(0) = 1.