A080429 - OEIS

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A080429

Odd numbers such that all a(i)*a(j) with i<j are distinct.

1, 3, 5, 7, 9, 11, 13, 17, 19, 23, 25, 29, 31, 37, 41, 43, 47, 49, 53, 59, 61, 67, 71, 73, 79, 81, 83, 89, 97, 101, 103, 105, 107, 109, 113, 121, 127, 131, 137, 139, 149, 151, 157, 163, 167, 169, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..60.

EXAMPLE

49 belongs to this sequence but 45 does not as 45*1 = 9*5.

MAPLE

S := {3}: A := array(1..10^3): for m from 1 to 10^3 do A[m] := 0 od: A[1] := 1: A[3] := 3: for n from 5 to 10^3-1 by 2 do mytest := 0: for j from 1 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 1 to n-2 by 2 do S := S union {A[j]*n} od: fi: od: for i from 1 to 10^3-1 by 2 do if A[i]>0 then printf(`%d, `, A[i]) fi: od: # James A. Sellers, Feb 25 2003

CROSSREFS

Cf. A062090.

Sequence in context: A061345 A238266 A308838 * A326581 A050150 A062090

Adjacent sequences: A080426 A080427 A080428 * A080430 A080431 A080432

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Feb 20 2003

EXTENSIONS

More terms from James A. Sellers, Feb 25 2003

STATUS

approved