Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 21.
A031519
Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 21.
Terms
- a(0) =443a(1) =451a(2) =459a(3) =463a(4) =467a(5) =479a(6) =487a(7) =491a(8) =499a(9) =503a(10) =511a(11) =523a(12) =527a(13) =1768a(14) =1832a(15) =1856a(16) =1888a(17) =1920a(18) =1952a(19) =2048a(20) =2080a(21) =2112a(22) =3975a(23) =4035a(24) =4119a(25) =4191a(26) =4395a(27) =4479a(28) =4611a(29) =4695
External references
- oeis: A031519