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 A028869 #16 Oct 27 2023 18:19:33 %S A028869 4,9,841,961 %N A028869 Squares of primes with digits in nonascending order. %C A028869 No other solutions below 4 * 10^18 (probably finite). - Dec 15 1999 %e A028869 961 = 31^2 is in the sequence since its digits (9, 6, 1) are in descending order. %e A028869 1369 = 37^2 is not in the sequence, since its digits in descending order are: 9, 6, 3, 1. %t A028869 Select[Prime[Range[100]]^2, IntegerDigits[#] == Sort[IntegerDigits[#], Less] &] (* _Alonso del Arte_, Aug 12 2016 *) %Y A028869 Cf. A028868, A028865, A028866. %K A028869 nonn,base,hard,more %O A028869 1,1 %A A028869 _Patrick De Geest_ %E A028869 Offset changed by _Altug Alkan_, Sep 09 2016 %E A028869 Name clarified by _Jon E. Schoenfield_, Oct 27 2023