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 A262137 #28 Oct 12 2015 12:11:08
%S A262137 300,250,214,188,167,150,136,125,115,107,100,94,88,83,79,75,71,68,65,
%T A262137 62,60,58,56,54,52,50,48,47,45,44,43,42,41,39,38,38,37,36,35,34,33,33,
%U A262137 32,31,31,30,29,29,28,28,27,27,26,26,25,25,25,24,24,23
%N A262137 a(n) = round(1500/(n + 5)).
%C A262137 "Fine-tuned" square counting method to directly read the heartbeat rate a(n) on EKG printout whereby in presence of similar occurring QRS wave complexes one such successive pair is considered (with the first QRS complex specifically spotted whose R wave _/|\_ falls sharply right on a thick marking) so that the ensuing R complex is read n smaller markings (or mm) farther off the first thick marking following the first spotted R thick-marking wave.
%C A262137 Sequence of first twenty entries or so is usually relevant and worth memorizing in clinical practice.
%D A262137 Dale Dubin, Rapid Interpretation Of EKG's, pp. 89, 335. COVER Pub. FL 2000.
%H A262137 J. S. S. G. de Jong, P. G. Postema, ECGpedia, <a href="http://en.ecgpedia.org/wiki/Rate">Rate: Fine-tuned square-counting method</a>
%H A262137 D. Dubin, Chapter 4: Rate, <a href="http://imagizer.imageshack.us/a/img673/4309/mSEyu3.jpg">page 89, 335</a>
%t A262137 Table[Round [1500/(n + 5)], {n, 0, 200}] (* _Vincenzo Librandi_, Sep 12 2015 *)
%o A262137 (PARI) first(m)=vector(m,i,i--;round(1500/(i + 5))) \\ _Anders Hellström_, Sep 12 2015
%K A262137 nonn,easy
%O A262137 0,1
%A A262137 _Lekraj Beedassy_, Sep 11 2015