Centered 40-gonal numbers.

Terms

a(0) =1a(1) =41a(2) =121a(3) =241a(4) =401a(5) =601a(6) =841a(7) =1121a(8) =1441a(9) =1801a(10) =2201a(11) =2641a(12) =3121a(13) =3641a(14) =4201a(15) =4801a(16) =5441a(17) =6121a(18) =6841a(19) =7601a(20) =8401a(21) =9241a(22) =10121a(23) =11041a(24) =12001a(25) =13001a(26) =14041a(27) =15121a(28) =16241a(29) =17401