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A087550 a(n) = smallest k such that for each r, 2 <= r <= n, there exists a distinct s, n < s <= k, with the same prime signature as r. 0

%I #5 Dec 05 2013 19:56:31

%S 3,7,9,13,13,19,27,49,49,49,49,49,49,49,81,81,81,81,81,81,81,81,81,

%T 169,169,343,343,343,343,343,343,343,343,343,343,343,343,343,343,343,

%U 343,343,343,343,343,343,343,361,361,361,361,361,361,361,361,361,361,361

%N a(n) = smallest k such that for each r, 2 <= r <= n, there exists a distinct s, n < s <= k, with the same prime signature as r.

%F For sufficiently large n, a(n) = 7^floor(log(n)/log(3)) because log(prime(2m))/log(prime(m)) is largest for m = 2. - _David Wasserman_, Jun 03 2005

%e a(7) = 19 and For numbers ( 2,3,4,5,6,7) we have the set of numbers ( 11,13,9,17,10,19) with matching prime signatures.

%K nonn

%O 2,1

%A _Amarnath Murthy_, Sep 13 2003

%E More terms from _David Wasserman_, Jun 03 2005

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Last modified April 25 04:42 EDT 2024. Contains 371964 sequences. (Running on oeis4.)