A140345 - OEIS

A140345

a(n)=a(n-1)^2-a(n-2)-a(n-3)-a(n-4), a(1)=a(2)=a(3)=a(4)=1.

1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2, 1, 1, 1, 1, -2

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OFFSET

1,5

COMMENTS

Periodic with period 5: 1,1,1,1,-2

LINKS

Table of n, a(n) for n=1..105.

Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 1).

FORMULA

a(n)=a(n-1)^2-a(n-2)-a(n-3)-a(n-4), a(1)=a(2)=a(3)=a(4)=1

EXAMPLE

a(5)=1^2-1-1-1=-2