This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A125237 #9 Sep 24 2019 06:46:01
%S A125237 3,9,10,18,50,100,104,121,136,289,464,576,650,900,5041,6962,7225,
%T A125237 10201,14400,55225,65025,87025,102152,147456,171698,174050,179776,
%U A125237 182329,189225,201601,222784,291848,312481,380689,410881,469225,481636,488601
%N A125237 Numbers n for which the absolute value of the abundance of both n and n^2 is a prime number.
%H A125237 Amiram Eldar, <a href="/A125237/b125237.txt">Table of n, a(n) for n = 1..500</a>
%e A125237 n=3: The abundance of 3 is -2, the negative of a prime. n^2=9, the abundance of 9 is -5, the negative of a prime as well.
%t A125237 pQ[n_] := PrimeQ[DivisorSigma[1, n] - 2n]; Select[Range[10^4], pQ[#] && pQ[#^2] &] (* _Amiram Eldar_, Sep 24 2019 *)
%o A125237 (PARI) {for(n=1, 500000, if(isprime(abs(sigma(n)-2*n)) && isprime(abs(sigma(n^2)-2*n^2)), print1(n, ",")))} \\ _Klaus Brockhaus_, Nov 25 2006
%Y A125237 Cf. A088005, A125236.
%K A125237 nonn
%O A125237 1,1
%A A125237 _Jason G. Wurtzel_, Nov 25 2006
%E A125237 More terms from _Klaus Brockhaus_, Nov 25 2006