A076673 Smallest a(n)>a(n-1) such that a(n)^2+a(n-1)^2 is a perfect square, a(1)=7.

7, 24, 32, 60, 63, 84, 112, 180, 189, 252, 275, 660, 693, 924, 1232, 1326, 1768, 1974, 2632, 4026, 5368, 6405, 8200, 8319, 11092, 11715, 15620, 16401, 19720, 20706, 20880, 20910, 24752, 24960, 25300, 26565, 29716, 29835, 33048, 35055, 41496

Offset: 1

Author

Zak Seidov, Oct 25 2002

Keywords

• nonn

Comments

The sequence is infinite.

Crossrefs

Cf. A076600.

Programs

Mathematica

nxt[n_]:= Module[{k = n + 1}, While[!IntegerQ[Sqrt[n^2 + k^2]], k++]; k]; NestList[nxt,7,40] (* Harvey P. Dale, May 29 2015 *)