%I #8 Jul 08 2019 12:10:06
%S 1,22,94,115,119,210,214,217,265,343,382,497,510,517,527,679,745,862,
%T 889,930,966,1155,1174,1177,1207,1219,1393,1416,1465,1501,1566,1624,
%U 1649,1672,1687,1915,1942,2101,2130,2159,2201,2226,2346,2359,2530,2618
%N Numbers k such that the number of positive divisors of k and the sum of the positive divisors of k are both square numbers.
%C These might be called square sublime numbers.
%H Amiram Eldar, <a href="/A145769/b145769.txt">Table of n, a(n) for n = 1..10000</a>
%e Number of divisors of 94 is 4 = 2^2, sum of divisors of 94 is 144 = 12^2. Hence 94 is in the sequence. [_Klaus Brockhaus_, Oct 21 2008]
%t aQ[n_] := AllTrue[{0,1}, IntegerQ[Sqrt[DivisorSigma[#, n]]] &]; Select[Range[2700], aQ] (* _Amiram Eldar_, Jul 08 2019 *)
%Y Cf. A023194.
%Y Cf. A000005 (number of divisors), A000203 (sum of divisors), A000290 (squares). [_Klaus Brockhaus_, Oct 21 2008]
%K nonn
%O 1,2
%A Howard Berman (howard_berman(AT)hotmail.com), Oct 18 2008
%E Extended by _Klaus Brockhaus_, Oct 21 2008
|