Structured heptagonal diamond numbers (vertex structure 5).

Terms

a(0) =1a(1) =9a(2) =34a(3) =86a(4) =175a(5) =311a(6) =504a(7) =764a(8) =1101a(9) =1525a(10) =2046a(11) =2674a(12) =3419a(13) =4291a(14) =5300a(15) =6456a(16) =7769a(17) =9249a(18) =10906a(19) =12750a(20) =14791a(21) =17039a(22) =19504a(23) =22196a(24) =25125a(25) =28301a(26) =31734a(27) =35434a(28) =39411a(29) =43675