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 A083749 #13 Dec 15 2017 17:36:20 %S A083749 121,253,793,1261,1633,2773,3901,11881,19153,24961,49141,50233,59401, %T A083749 90037,128773,162361,186913,197653,268393,294373,422941,492493, %U A083749 1425937,1515037,1663213,1811701,2092141,2185273,2601733,3020341,3063061 %N A083749 Brilliant star numbers: semiprimes of the form 6n^2 - 6n + 1 such that both prime factors have the same number of decimal digits. %C A083749 Brilliant numbers are A078972; "star numbers" here refers to centered 12-gonal numbers A003154, but there exist other definitions for this name. - _M. F. Hasler_, Nov 01 2012 %Y A083749 Intersection of A003154 and A078972, or of A218172 and A078972. %Y A083749 Cf. A063773. %K A083749 base,nonn %O A083749 1,1 %A A083749 _Jason Earls_, Jun 17 2003 %E A083749 Definition clarified by _Charles R Greathouse IV_, Nov 01 2012