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%I #8 Mar 24 2019 22:46:04
%S 0,1,2,3,4,7,6,7,14,9,10,19,12,16,49,29,29,35,18,19,32,21,22,43,24,29,
%T 36,46,57,59,30,31,55,71,73,103,36,37,71,107,68,41,42,57,44,45,58,103,
%U 48,49,82,62,163,157,54,55,86,68,199,179,60
%N a(0)=0; a(n) = n-th integer from among those positive integers which are coprime to (a(n-1) + n).
%e a(13) + 14 = 30. The positive integrs which are coprime to 30 are 1, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 49, 53, 59, 61, ...; the 14th of these integers is 49, so a(14) = 49.
%p a[0]:=0: for n to 60 do CP:={}: for j while nops(CP)<=n do if gcd(n+a[n-1],j) =1 then CP:=`union`(CP,{j}) else end if end do: a[n]:=CP[n] end do: seq(a[n], n=0..60); # _Emeric Deutsch_, Aug 28 2007
%K nonn
%O 0,3
%A _Leroy Quet_, Aug 12 2007
%E More terms from _Emeric Deutsch_, Aug 28 2007