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 A237284 #14 Mar 13 2020 13:28:38 %S A237284 0,0,1,2,2,1,2,3,2,2,4,3,1,3,2,1,5,3,1,3,3,3,4,5,2,3,4,1,4,3,3,6,2,1, %T A237284 6,6,3,4,7,1,4,6,3,5,6,2,4,4,2,6,5,3,5,4,3,7,8,2,4,8,1,4,5,3,6,5,4,2, %U A237284 7,5,6,6,3,4,6,2,5,7,2,4 %N A237284 Number of ordered ways to write 2*n = p + q with p, q and A000720(p) all prime. %C A237284 Conjecture: a(n) > 0 for all n > 2, and a(n) = 1 only for n = 3, 6, 13, 16, 19, 28, 34, 40, 61, 166, 278. %C A237284 This is stronger than Goldbach's conjecture. %C A237284 The conjecture is true for n <= 5*10^8. - _Dmitry Kamenetsky_, Mar 13 2020 %H A237284 Zhi-Wei Sun, <a href="/A237284/b237284.txt">Table of n, a(n) for n = 1..10000</a> %H A237284 Carlos Rivera, <a href="https://www.primepuzzles.net/conjectures/conj_085.htm">Conjecture 85. Conjectures stricter that the Goldbach ones</a>, Prime Puzzles %H A237284 Z.-W. Sun, <a href="http://arxiv.org/abs/1402.6641">Problems on combinatorial properties of primes</a>, arXiv:1402.6641 [math.NT], 2014-2016. %e A237284 a(13) = 1 since 2*13 = 3 + 23 with 3, 23 and A000720(3) = 2 all prime. %e A237284 a(278) = 1 since 2*278 = 509 + 47 with 509, 47 and A000720(509) = 97 all prime. %t A237284 a[n_]:=Sum[If[PrimeQ[2n-Prime[Prime[k]]],1,0],{k,1,PrimePi[PrimePi[2n-1]]}] %t A237284 Table[a[n],{n,1,80}] %Y A237284 Cf. A000040, A000720, A002372, A002375, A006450, A236566. %K A237284 nonn %O A237284 1,4 %A A237284 _Zhi-Wei Sun_, Feb 06 2014