Stellated octagon numbers: a(n) = 20*n^2 + 8*n + 1.

Terms

a(0) =1a(1) =29a(2) =97a(3) =205a(4) =353a(5) =541a(6) =769a(7) =1037a(8) =1345a(9) =1693a(10) =2081a(11) =2509a(12) =2977a(13) =3485a(14) =4033a(15) =4621a(16) =5249a(17) =5917a(18) =6625a(19) =7373a(20) =8161a(21) =8989a(22) =9857a(23) =10765a(24) =11713a(25) =12701a(26) =13729a(27) =14797a(28) =15905a(29) =17053