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 A115695 #5 Mar 30 2012 17:40:35 %S A115695 1,100,500,529,1000,1089,2116,5000,6241,10000,50000,52900,100000, %T A115695 103041,108900,151875,211600,500000,529000,549152,624100,1000000, %U A115695 1089000,2116000,5000000,5290000,6241000,10000000 %N A115695 Powerful(1) numbers (A001694) whose digit reversal is a pentagonal number (A000326). %H A115695 <a href="/index/Pow#powerful">Index entries for sequences related to powerful numbers</a> %e A115695 529=23^2 is powerful and 925 is the 25th pentagonal number. %Y A115695 Cf. A000326, A001694, A115696. %K A115695 nonn,base %O A115695 1,2 %A A115695 _Giovanni Resta_, Jan 31 2006