Partial sums of A008531, or crystal ball sequence for {A_4}* lattice.

Terms

a(0) =1a(1) =11a(2) =61a(3) =211a(4) =551a(5) =1201a(6) =2311a(7) =4061a(8) =6661a(9) =10351a(10) =15401a(11) =22111a(12) =30811a(13) =41861a(14) =55651a(15) =72601a(16) =93161a(17) =117811a(18) =147061a(19) =181451a(20) =221551a(21) =267961a(22) =321311a(23) =382261a(24) =451501a(25) =529751a(26) =617761a(27) =716311a(28) =826211a(29) =948301