X-toothpick sequence on Z^3 lattice (see Comments for precise definition).

Terms

a(0) =0a(1) =1a(2) =5a(3) =13a(4) =21a(5) =45a(6) =77a(7) =109a(8) =165a(9) =245a(10) =325a(11) =413a(12) =525a(13) =685a(14) =853a(15) =1093a(16) =1317a(17) =1661a(18) =1981a(19) =2301a(20) =2645a(21) =3093a(22) =3621a(23) =4157a(24) =4861a(25) =5565a(26) =6437a(27) =7173a(28) =8053a(29) =8893