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 A066805 #7 Aug 01 2020 11:37:42
%S A066805 1,1,5,1,6,1,8,2,5,1,7,1,5,2,5,1,7,1,5,3,6,1,6,2,5,2,13,1,6,1,5,2,5,4,
%T A066805 6,1,8,2,5,1,6,1,5,10,5,1,7,2,8,3,5,1,7,2,5,2,7,1,6,1,5,2,6,4,6,1,8,2,
%U A066805 5,1,6,1,5,2,5,27,7,1,5,11,5,1,15,2,5
%N A066805 a(n) is the least k such that n + Sum_{i=1..k} A018252(i) is prime; or 0 if none exists.
%C A066805 Is a(n) nonzero for all n? If so, then every n can be represented as the difference of a prime and a partial sum of the nonprime numbers series. See A066753 for a related possible representation of n as the difference of a prime and a partial sum of the prime numbers series.
%e A066805 3 + (1 + 4 + 6 + 8 + 9) = 31, a prime and 5 consecutive nonprime numbers starting with 1 are required to achieve this. Hence a(3) = 5.
%o A066805 (PARI) a(n) = my(c=0, s=n); for(k=1, oo, until(!isprime(c), c++); if(isprime(s+=c), return(k))); \\ _Jinyuan Wang_, Jul 30 2020
%Y A066805 Cf. A018252, A066753.
%K A066805 nonn
%O A066805 1,3
%A A066805 _Joseph L. Pe_, Jan 19 2002
%E A066805 More terms from Larry Reeves (larryr(AT)acm.org), Jun 12 2002