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A080431 Even numbers such that all a(i)*a(j) are distinct. 2

%I #10 Dec 23 2014 04:21:49

%S 2,4,6,8,10,14,18,22,26,32,34,38,46,50,58,60,62,74,82,86,94,98,106,

%T 118,122,134,142,146,158,162,166,168,178,194,202,206,214,218,226,242,

%U 254,256,262,274,278,298,302,308,314,326,334,338,346,358,360,362,382,386

%N Even numbers such that all a(i)*a(j) are distinct.

%p S := {8}: A := array(1..10^3): for m from 1 to 10^3 do A[m] := 0 od: A[2] := 2: A[4] := 4: for n from 6 to 10^3 by 2 do mytest := 0: for j from 2 to n-2 by 2 do if A[j]>0 then if member(A[j]*n, S) then mytest := 1; break; fi: fi: od: if mytest=0 then A[n] := n; for j from 2 to n-2 by 2 do S := S union {A[j]*n} od: fi: od: for i from 2 to 10^3 by 2 do if A[i]>0 then printf(`%d,`, A[i]) fi: od: # _James A. Sellers_, Feb 26 2003

%Y Cf. A080430, A080432.

%Y Equals 2*A066724.

%K nonn

%O 1,1

%A _Amarnath Murthy_, Feb 20 2003

%E More terms from _James A. Sellers_, Feb 26 2003

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Last modified March 28 13:25 EDT 2024. Contains 371254 sequences. (Running on oeis4.)