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 A004239 #9 Apr 02 2025 18:08:07 %S A004239 0,70,110,139,161,180,195,208,220,231,240,249,257,264,271,278,284,290, %T A004239 295,300,305,310,314,318,322,326,330,334,337,341,344,347,350,353,356, %U A004239 359,362,364,367,369,372,374,377 %N A004239 a(n) = ceiling(100*log(n)). %t A004239 Ceiling[100 Log[Range[50]]] (* _Harvey P. Dale_, Apr 02 2025 *) %K A004239 nonn %O A004239 1,2 %A A004239 _N. J. A. Sloane_