Löschian numbers (A003136) of the form k^2+1.

Terms

a(0) =1a(1) =37a(2) =325a(3) =577a(4) =1297a(5) =2917a(6) =3601a(7) =4357a(8) =7057a(9) =8101a(10) =9217a(11) =14401a(12) =15877a(13) =22501a(14) =24337a(15) =28225a(16) =32401a(17) =41617a(18) =44101a(19) =46657a(20) =57601a(21) =60517a(22) =69697a(23) =72901a(24) =79525a(25) =86437a(26) =90001a(27) =93637a(28) =108901a(29) =133957