Centered 21-gonal numbers.

Terms

a(0) =1a(1) =22a(2) =64a(3) =127a(4) =211a(5) =316a(6) =442a(7) =589a(8) =757a(9) =946a(10) =1156a(11) =1387a(12) =1639a(13) =1912a(14) =2206a(15) =2521a(16) =2857a(17) =3214a(18) =3592a(19) =3991a(20) =4411a(21) =4852a(22) =5314a(23) =5797a(24) =6301a(25) =6826a(26) =7372a(27) =7939a(28) =8527a(29) =9136