Numbers k such that the continued fraction for sqrt(k) has period 4.

Terms

a(0) =7a(1) =14a(2) =23a(3) =28a(4) =32a(5) =33a(6) =34a(7) =47a(8) =55a(9) =60a(10) =62a(11) =75a(12) =78a(13) =79a(14) =95a(15) =96a(16) =98a(17) =119a(18) =126a(19) =128a(20) =136a(21) =138a(22) =140a(23) =141a(24) =142a(25) =155a(26) =167a(27) =174a(28) =176a(29) =180