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a(n) = T(n,n), array T as in A049615.
4

%I #7 Dec 16 2019 22:09:51

%S 0,0,3,6,11,14,23,26,35,42,55,58,75,78,95,110,127,130,155,158,183,202,

%T 227,230,263,274,303,322,355,358,403,406,439,466,503,526,575,578,619,

%U 650,699,702,763,766,815,858,907,910,975,990,1051,1090,1147,1150,1223,1254,1319,1362,1423,1426,1515,1518,1583

%N a(n) = T(n,n), array T as in A049615.

%H G. C. Greubel, <a href="/A049620/b049620.txt">Table of n, a(n) for n = 0..1000</a>

%t T[n_, k_]:= Length[Select[Flatten[Table[{x, y}, {x,0,n}, {y,0,k}], 1], GCD @@ # > 1 &]]; Table[T[n, n], {n,0,65}] (* _G. C. Greubel_, Dec 16 2019 *)

%Y Cf. A049615, A049616, A049617, A049618, A049619, A049621, A049622, A049623.

%K nonn

%O 0,3

%A _Clark Kimberling_

%E Terms a(38) onward added by _G. C. Greubel_, Dec 16 2019