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 A083128 #9 Jul 08 2023 14:14:03 %S A083128 8,12,105,1331,10013,100181,1030301,10000127,100000727,1027243729, %T A083128 10000002797,100000000757,1002101470343,10000000000493, %U A083128 100000000005643,1000090002700027,10000000000001251,100000000000000649 %N A083128 Least 3-brilliant number of size n. %C A083128 Brilliant numbers, as defined by Peter Wallrodt, are numbers with two prime factors of the same length (in decimal notation). These numbers are generally used for cryptographic purposes and for testing the performance of prime factoring programs. %C A083128 a(3n+1) will always be the cube of the least prime greater than 10^n. %C A083128 2-brilliant numbers are A078972. 3-brilliant numbers addressed in A083128 and A083182. The sum of all 1, 2 and 3-digit 2-brilliant numbers is a 3-brilliant number. 37789 = 23 * 31 * 53 = 4 + 6 + 9 + 10 + 14 + 15 + 21 + 25 + 35 + 49 + 121 + 143 + 169 + 187 + 209 + 221 + 247 + 253 + 289 + 299 + 319 + 323 + 341 + 361 + 377 + 391 + 403 + 407 + 437 + 451 + 473 + 481 + 493 + 517 + 527 + 529 + 533 + 551 + 559 + 583 + 589 + 611 + 629 + 649 + 667 + 671 + 689 + 697 + 703 + 713 + 731 + 737 + 767 + 779 + 781 + 793 + 799 + 803 + 817 + 841 + 851 + 869 + 871 + 893 + 899 + 901 + 913 + 923 + 943 + 949 + 961 + 979 + 989 - _Jonathan Vos Post_, Jun 17 2007 %H A083128 Dario Alpern, <a href="https://www.alpertron.com.ar/BRILLIANT.HTM">Brilliant numbers</a> %e A083128 a(5) = 10013 = 17 * 19 * 31 and there is no lesser number of five digits which has three prime factors, not necessarily different, of the same size in decimal notation. %Y A083128 Cf. A083182. %Y A083128 Cf. A078972, A083128, A083182. %K A083128 nonn,base %O A083128 1,1 %A A083128 _Robert G. Wilson v_, May 11 2003