Centered dodecahedral numbers.

Terms

a(0) =1a(1) =33a(2) =155a(3) =427a(4) =909a(5) =1661a(6) =2743a(7) =4215a(8) =6137a(9) =8569a(10) =11571a(11) =15203a(12) =19525a(13) =24597a(14) =30479a(15) =37231a(16) =44913a(17) =53585a(18) =63307a(19) =74139a(20) =86141a(21) =99373a(22) =113895a(23) =129767a(24) =147049a(25) =165801a(26) =186083a(27) =207955a(28) =231477a(29) =256709