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 A280008 #24 Feb 21 2017 21:16:23 %S A280008 0,1,0,1,-1,1,0,0,0,1,0,0,-1,1,-1,2,0,-2,1,1,-1,1,1,-1,-1,2,-2,1,2,-3, %T A280008 2,1,-4,3,1,-1,0,2,-3,1,3,-3,-1,5,-5,1,2,-4,3,2,-3,1,2,-2,1,3,-4,0,6, %U A280008 -8,1,5,-7,4,2,-3,-1,3,-1,1,3,-5,-1,7,-8,4,3,-6,3,2,-5,1,7,-4,-3,5,-4,0,7,-8,2,5,-8,3,3,-4,2,4,-5,1,5,-7,0,12,-13,2,5,-6,2,2,-4,0,5,-3,-2,8,-6,0,9,-10 %N A280008 First differences of A002375. %C A280008 See the perception of symmetry on scatterplot of this sequence that is also in Links section. %C A280008 Are there infinitely many 0's in this sequence? %H A280008 Altug Alkan, <a href="/A280008/b280008.txt">Table of n, a(n) for n = 1..10000</a> %H A280008 Altug Alkan, <a href="/A280008/a280008.png">Alternative Scatterplot of A280008</a> %F A280008 a(n) = A002375(n+1) - A002375(n). %o A280008 (PARI) a002375(n) = sum(i=2, primepi(n), isprime(2*n - prime(i))); %o A280008 a(n) = a002375(n+1) - a002375(n); %Y A280008 Cf. A002375, A282778. %K A280008 sign %O A280008 1,16 %A A280008 _Altug Alkan_, Feb 21 2017