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%I #14 Apr 14 2017 12:18:08
%S 1,3,43,68,93,228,612,1903,32292,44868,252072,36564198,55862807,
%T 134735264
%N Numbers n such that the sum of the first k divisors of n^2+1 is equal to n for some k.
%C No further at least up to 10^7.
%C No other terms up to 10^8. - _Michel Marcus_, Jan 17 2014
%C a(15) > 2.5*10^8. - _Giovanni Resta_, Apr 14 2017
%e The divisors of 43^2 + 1 are {1, 2, 5, 10, 25, 37, 50, 74, 185, 370, 925, 1850} and 1+2+5+10 + 25 = 43, hence 43 is in the list.
%t Select[Range[10000000], MemberQ[Accumulate[Divisors[#^2+1]], #]&]
%Y Cf. A185584.
%K nonn
%O 1,2
%A _Michel Lagneau_, Aug 29 2011
%E a(12)-a(13) from _Michel Marcus_, Jan 17 2014
%E a(14) from _Giovanni Resta_, Apr 14 2017
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