Series for first parallel moment of square lattice.

Terms

a(0) =0a(1) =2a(2) =8a(3) =22a(4) =52a(5) =112a(6) =228a(7) =442a(8) =832a(9) =1516a(10) =2720a(11) =4754a(12) =8264a(13) =14000a(14) =23824a(15) =39318a(16) =66052a(17) =106282a(18) =177884a(19) =277936a(20) =469384a(21) =703924a(22) =1225052a(23) =1718226a(24) =3203156a(25) =3974696a(26) =8551248a(27) =8307370a(28) =23950704a(29) =13195606