1,2

The corresponding sequence for which 5n^2+4 is a square is A001906 (a bisection of the Fibonacci sequence).

It appears that a(n)=18a(n-2)-a(n-4).

25 is a term of the sequence since 5*25^2 + 11 = 56^2.

Cf. A001906, A080806.

Adjacent sequences: A082648 A082649 A082650 this_sequence A082652 A082653 A082654

Sequence in context: A138292 A138738 A057573 this_sequence A088009 A081298 A012490

nonn

John W. Layman (layman(AT)math.vt.edu), May 16 2003