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 A141099 #4 Mar 30 2012 17:22:50 %S A141099 1,0,0,0,1,0,0,1,1,0,1,1,1,1,2,0,2,3,0,2,3,1,2,3,3,2,4,2,3,5,1,4,6,1, %T A141099 5,5,3,4,7,3,4,7,4,4,9,4,5,8,4,7,9,5,6,8,6,7,10,6,6,13,5,7,13,5,10,11, %U A141099 8,8,11,9,10,14,9,9,16,7,12,15,8,12,15,9,10,17,14,11,16,12,12,19,11,13,19 %N A141099 Number of unordered pairs of odd nonprime numbers that sum to 2n. %C A141099 See A141100 for pairs of odd composite numbers. We have a(n) > 0 except for the 8 values of 2n given in A046458. %H A141099 T. D. Noe, <a href="/A141099/b141099.txt">Table of n, a(n) for n=1..1000</a> %e A141099 a(18)=3 because 36 = 1+35 = 9+27 = 15+21. %t A141099 Table[cnt=0; Do[If[ !PrimeQ[i] && !PrimeQ[2n-i], cnt++ ], {i,1,n,2}]; cnt, {n,100}] %Y A141099 Cf. A141095, A141097. %K A141099 nonn %O A141099 1,15 %A A141099 _T. D. Noe_, Jun 02 2008, Jun 05 2008