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A093866 a(0)=1, then a(n) is the least number such that there are exactly n numbers coprime to a(n-1) between a(n-1) and a(n) (excluded). 0

%I #6 Nov 18 2018 01:17:59

%S 1,3,6,14,24,38,50,68,84,114,146,168,210,264,308,348,398,432,486,542,

%T 582,644,698,744,818,868,930,1034,1098,1188,1286,1348,1412,1478,1546,

%U 1616,1688,1762,1838,1916,1996,2078,2162,2254,2362,2452,2544,2688,2856

%N a(0)=1, then a(n) is the least number such that there are exactly n numbers coprime to a(n-1) between a(n-1) and a(n) (excluded).

%C Obviously, from a(3) onwards, all terms are even.

%e a(5) = 24, a(6) = 38, and the five numbers coprime to 24 are 25, 29, 31, 35 and 37.

%t k = 1; Print[k]; Do[v = 0; m = k + 1; While[v < n, If[GCD[m, k] == 1, v++ ]; m++ ]; k = m; Print[k], {n, 1, 50}] (* _Ryan Propper_, Jul 25 2005 *)

%K nonn

%O 0,2

%A _Amarnath Murthy_, Apr 20 2004

%E More terms from _Ryan Propper_, Jul 25 2005

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