Centered heptagonal numbers.

Terms

a(0) =1a(1) =8a(2) =22a(3) =43a(4) =71a(5) =106a(6) =148a(7) =197a(8) =253a(9) =316a(10) =386a(11) =463a(12) =547a(13) =638a(14) =736a(15) =841a(16) =953a(17) =1072a(18) =1198a(19) =1331a(20) =1471a(21) =1618a(22) =1772a(23) =1933a(24) =2101a(25) =2276a(26) =2458a(27) =2647a(28) =2843a(29) =3046