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 A025145 #13 Jan 09 2024 16:10:43 %S A025145 27,36,802,804,810,822,937,943,944,945,947,949,952,955,973,980,998, %T A025145 1007,1025,1033,1042,1045,1051,1052,1053,1060,1063,1069,1072,1075, %U A025145 1078,1087,1133 %N A025145 Numbers k such that (#1's in s(1),...,s(k)) = -1 + (#1's in r(1),...,r(k)), where s = A025142 and r = A025143. %H A025145 H. Harborth, <a href="https://doi.org/10.1007/s005910050025">Probleme und Lösungen</a>, Mathematische Semesterberichte 44 (1997) 94. %K A025145 nonn %O A025145 1,1 %A A025145 _Clark Kimberling_