Szeged index of the grid graph P_3 X P_n.

Terms

a(0) =4a(1) =59a(2) =216a(3) =526a(4) =1040a(5) =1809a(6) =2884a(7) =4316a(8) =6156a(9) =8455a(10) =11264a(11) =14634a(12) =18616a(13) =23261a(14) =28620a(15) =34744a(16) =41684a(17) =49491a(18) =58216a(19) =67910a(20) =78624a(21) =90409a(22) =103316a(23) =117396a(24) =132700a(25) =149279a(26) =167184a(27) =186466a(28) =207176a(29) =229365