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 A213531 #7 Feb 04 2017 01:21:14 %S A213531 0,11,201,2592,29916,328988,3550745,37432690,390065916,4034529147, %T A213531 41532029309,425608837164 %N A213531 Number of k < 10^n such that A047988(k) = 2. %D A213531 Thomas Kantke, Mathematische Unterhaltungen, in: Spektrum der Wissenschaft 4/1993, p. 11-13. %D A213531 Thomas Kantke, Das Spiel Minimum, in: Spektrum der Wissenschaft Spezial Physik - Mathematik - Technik 2/2012, pp. 57-66. %Y A213531 Cf. A047985, A047988, A212524, A213530, A213532, A213533. %K A213531 nonn %O A213531 1,2 %A A213531 _Martin Renner_, Jun 13 2012