Denominators of the Harary index of the n X n grid graph.

Terms

a(0) =1a(1) =1a(2) =6a(3) =5a(4) =28a(5) =630a(6) =396a(7) =9009a(8) =24024a(9) =87516a(10) =1511640a(11) =5819814a(12) =4576264a(13) =106234700a(14) =1147334760a(15) =1890494775a(16) =11031593040a(17) =343817983080a(18) =292314884400