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 A199425 #8 Jul 13 2013 12:04:18 %S A199425 0,0,1,2,4,5,8,10,13,17,20,24,30,35,42,49,57,63,71,80,90,99,110,121, %T A199425 133,145,157,170,184,197,212,227,242,258,275,292,310,327,345,364,384, %U A199425 404,425,446,467,489,512,535,558,581,606,630,656,682,709,736,764 %N A199425 Number of distinct primes in rows 0 through n of the triangle in A199333. %H A199425 Reinhard Zumkeller, <a href="/A199425/b199425.txt">Table of n, a(n) for n = 0..150</a> %o A199425 (Haskell) %o A199425 import Data.List (union) %o A199425 a199425 n = a199425_list !! n %o A199425 a199425_list = f [] a199333_tabl where %o A199425 f ps (ts:tts) = (length ps') : f ps' tts where %o A199425 ps' = ps `union` (take ((length ts - 1) `div` 2) $ tail ts) %Y A199425 Cf. A199424, A126256. %K A199425 nonn %O A199425 0,4 %A A199425 _Reinhard Zumkeller_, Nov 09 2011