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 A049306 #29 Feb 01 2025 23:20:01 %S A049306 4,6,7,10,13,17,18,28,31,33,36,38,42,44,47,48,49,52,54,56,58,60,63,64, %T A049306 67,68,69,76,77,79,81,82,83,85,86,89,90,91,94,97,112,115,124,130,135, %U A049306 165,173,176,178,189,193,195,206,208,215,221,225,249,251,252,253,256 %N A049306 Numbers k such that k is a substring of 8^k. %H A049306 David A. Corneth, <a href="/A049306/b049306.txt">Table of n, a(n) for n = 1..10000</a> %t A049306 Select[Range[300],SequenceCount[IntegerDigits[8^#],IntegerDigits[#]]>0&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Dec 16 2018 *) %o A049306 (Python) %o A049306 def ok(n): return str(n) in str(8**n) %o A049306 print(list(filter(ok, range(257)))) # _Michael S. Branicky_, Aug 13 2021 %Y A049306 Cf. A001018, A032740, A049301, A049302, A049303, A049304, A049305, A049307. %K A049306 nonn,base,easy %O A049306 1,1 %A A049306 _David W. Wilson_