%I #9 Oct 11 2019 14:05:29
%S 1,5,5,13,7,35,9,29,19,43,13,83,15,55,44,61,19,115,21,103,55,79,25,
%T 179,38,89,59,129,31,269,33,125,79,113,69,271,39,125,89,223,43,335,45,
%U 183,146,149,49,371,66,231,113,211,55,359,98,279,125,185,61,629,63,197,181
%N a(n) = (sum of the divisors of n)th integer from among those positive integers which are coprime to n.
%e 8 = 1 + 7 is the sum of the divisors of 7. 1,2,3,4,5,6,8,9,10,11,12,13,15,16,... are the positive integers
%e which are coprime to 7. Of these integers, 9 is the 8th. So a(7) = 9.
%t f[n_] := Block[{c = DivisorSigma[1, n], k = 0}, While[c > 0, k++; While[GCD[n, k] > 1, k++ ]; c-- ]; k ]; Table[f[n], {n, 63}] (* _Ray Chandler_, Aug 29 2006 *)
%Y Cf. A122212.
%K nonn
%O 1,2
%A _Leroy Quet_, Aug 26 2006
%E Extended by _Ray Chandler_, Aug 29 2006