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 A049307 #18 Feb 01 2025 20:30:01 %S A049307 5,7,9,25,26,31,37,43,46,47,48,53,59,60,61,63,68,69,70,72,74,76,80,85, %T A049307 87,88,89,91,94,97,101,104,107,124,132,135,140,148,158,166,170,180, %U A049307 187,190,199,209,211,215,231,243,244,256,266,270,271,279,283,288,289,291 %N A049307 Numbers k such that k is a substring of 9^k. %Y A049307 Cf. A032740, A049301, A049302, A049303, A049304, A049305, A049306. %K A049307 nonn,base,easy %O A049307 1,1 %A A049307 _David W. Wilson_