Number of n X n arrays of squares of integers summing to 5.

Terms

a(0) =12a(1) =198a(2) =4608a(3) =53730a(4) =378252a(5) =1909236a(6) =7628544a(7) =25628076a(8) =75297420a(9) =198807114a(10) =481029120a(11) =1082267550a(12) =2289691404a(13) =4595197320a(14) =8809614336a(15) =16225724664a(16) =28845544716a(17) =49690719342a(18) =83218759680a(19) =135872231418a(20) =216792905868a(21) =338738351292a(22) =519244496640a(23) =782084374500