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 A194429 #9 Jan 08 2025 10:41:48 %S A194429 110,120,121,130,131,132,140,141,142,143,150,151,152,153,154,160,161, %T A194429 162,163,164,165,170,171,172,173,174,175,176,180,181,182,183,184,185, %U A194429 186,187,190,191,192,193,194,195,196,197,198,220,230,231,240,241,242,250,251,252,253,260,261,262,263,264,270,271,272,273,274,275,280,281 %N A194429 Numbers n such that there is no i >= 0 for which A053392(i) = n. %C A194429 The Friedman web site quotes B. J. van der Zwaag as saying that the three-digit terms are those for which the middle digit is >= the sum of the other two digits. %H A194429 Erich Friedman, <a href="https://erich-friedman.github.io/mathmagic/0200.html">Problem of the Month (February 2000)</a>. %Y A194429 Cf. A053392. %K A194429 nonn,base %O A194429 1,1 %A A194429 _N. J. A. Sloane_, Aug 24 2011