Crystal ball sequence for A_4 lattice.

Terms

a(0) =1a(1) =21a(2) =131a(3) =471a(4) =1251a(5) =2751a(6) =5321a(7) =9381a(8) =15421a(9) =24001a(10) =35751a(11) =51371a(12) =71631a(13) =97371a(14) =129501a(15) =169001a(16) =216921a(17) =274381a(18) =342571a(19) =422751a(20) =516251a(21) =624471a(22) =748881a(23) =891021a(24) =1052501a(25) =1235001a(26) =1440271