n times n+5 gives the concatenation of two numbers m and m+6.

Terms

a(0) =456a(1) =540a(2) =7666a(3) =72722a(4) =356430a(5) =643566a(6) =9090911a(7) =35294119a(8) =64705877a(9) =335664330a(10) =664335666a(11) =684210521a(12) =818181820a(13) =838056675a(14) =846153848a(15) =866028703a(16) =980125140a(17) =3861386140a(18) =6138613856a(19) =6916125390a(20) =9222488468a(21) =41358246491