A105737 For n>2, a(n) > 0 is such that a(n-1)^2+4*a(n-2)*a(n) is a minimal square, a(1)=1,a(2)=4.

1, 4, 5, 6, 8, 8, 6, 2, 4, 6, 4, 2, 2, 4, 6, 4, 2, 2, 4, 6, 4, 2

Offset

1,2

Comments

The sequence depends on seed terms a(1) and a(2); if a(1)=1, a(3)=a(2)+1. All(?) sequences end with cycle={1,2,3,2,1} (or {2,4,6,4,2}, which essentially the same cycle) of length=5. This particular sequence does not merge with A105734 - A105736 and ends with another cycle {2,4,6,4,2}.

Links

Table of n, a(n) for n=1..22.

Crossrefs

Cf. A105734 - A105746.

Sequence in context: A187807 A051036 A063673 * A335186 A257816 A033597

Adjacent sequences: A105734 A105735 A105736 * A105738 A105739 A105740

Keyword

nonn

Author

Zak Seidov, Apr 19 2005

Status

approved