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 A247815 #4 Sep 26 2014 13:27:26 %S A247815 0,1,1,3,2,5,3,5,5,7,4,9,5,9,7,10,6,14,7,13,10,13,8,18,10,14,11,16,9, %T A247815 26,10,17,14,18,13,26,11,20,16,23,12,31,13,22,21,22,14,32,15,28,20,27, %U A247815 15,35,19,29,22,28,16,45,17,29,27,30,21,44,18,32,26 %N A247815 Number of primes in n-th row of triangle A077581. %C A247815 a(n) = n - A247892(n). %H A247815 Reinhard Zumkeller, <a href="/A247815/b247815.txt">Table of n, a(n) for n = 1..10000</a> %F A247815 a(n) = A000720(A069213(n)) - A001221(n). %o A247815 (Haskell) %o A247815 a247815 = sum . map a010051' . a077581_row %Y A247815 Cf. A000720, A001221, A010051, A069213, A077581, A247892. %K A247815 nonn %O A247815 1,4 %A A247815 _Reinhard Zumkeller_, Sep 26 2014