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 A287613 #18 Jul 01 2017 07:48:40 %S A287613 36,97,138,206,358,402,722,2816,3205,3725,3918,3962,5020,5516,7461, %T A287613 8368,8756,9193,9621,10247,11219,11586,11759,12365,12580,12602,13164, %U A287613 13401,14892,15820,17743,18305,19644,20140,22344,24785,29733,32626,33276,34549,34615,35888 %N A287613 Ulam numbers u such that 5*u is also an Ulam number. %C A287613 As in the case k=2, these are very scarce Ulam numbers u with the property that k*u is also an Ulam number (see link). %H A287613 Enrique Navarrete, <a href="/A287613/a287613.pdf">Relative Frequencies of Multiples of Ulam Numbers</a> %Y A287613 Cf. A002858, A068791, A285885, A287612. %K A287613 nonn %O A287613 1,1 %A A287613 _Enrique Navarrete_, May 27 2017