A105734 For n>2, a(n) > 0 is such that a(n-1)^2+4*a(n-2)*a(n) is a minimal square, with a(1)=1, a(2)=1.

1, 1, 2, 3, 2, 1, 1, 2, 3, 2, 1, 1, 2, 3, 2, 1, 1, 2, 3, 2, 1, 1

Offset

1,3

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.

Links

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

Crossrefs

Cf. A105736 - A105746.

Sequence in context: A083279 A306239 A159455 * A076839 A092542 A321305

Adjacent sequences: A105731 A105732 A105733 * A105735 A105736 A105737

Keyword

nonn

Author

Zak Seidov, Apr 18 2005

Status

approved