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 A280134 #15 Dec 27 2016 23:12:30 %S A280134 0,0,1,0,1,1,1,1,1,0,1,2,2,1,1,1,2,2,3,2,3,3,2,1,2,2,2,2,1,1,2,2,3,3, %T A280134 2,2,3,2,3,3,1,4,3,1,4,3,2,3,4,3,2,5,3,2,4,2,4,4,3,4,4,3,3,5,2,2,6,4, %U A280134 2,5,4,3,6,3,2,3,4,4,5,3,2,6,4,3,5,1,5,6,2,3,4,4,3,6,3,4,8,3,3,4,3,3,5,2,2,6,4,3,6,5 %N A280134 Number of primes of the form 4(n - k - 1) + 3 where 0 <= k and prime of the form 4k + 3 <= n. %C A280134 (1) Conjecture: a(n) > 0 for n >= 11. %C A280134 (2) Conjecture: A278287(n) > 0 for n >= 11. %C A280134 Conjecture (1) and conjecture (2) are first and second parts of Goldbach-like conjecture in A001031. %e A280134 a(12) = 2 because 4*(12-0-1)+3 = 47 and 4*0+3 = 3 are primes where 3 < 12 and 4*(12-1-1)+3 = 43 and 4*1+3 = 7 are primes where 7 < 12. %Y A280134 Cf. A001031, A002144, A278287. %K A280134 nonn %O A280134 1,12 %A A280134 _Juri-Stepan Gerasimov_, Dec 26 2016