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 A089294 #3 Mar 31 2012 14:40:28 %S A089294 19,13,19,13,2,3,13,19,13,3,13,7,5,3,13,7,5,13,13,7,5,5,13,13,7,5,13, %T A089294 13,7,5,5,13,13,7,5,13,7,7,5,13,7,17,11,11,7,7,17,11,13,7,17,11,11,7, %U A089294 7,17,11,13,7,11,11,7,7,11,13,7,17,11,11,7,7,17,11,13,7,17,11,11,7,7,17,11 %N A089294 Smallest prime p_k such that n can be written as a "plus-minus" sum n=sum_(i=1..k)e_i*(p_i)^2 with distinct primes p_i<=p_k, where e_i is 1 or -1. %C A089294 The first terms where this sequence differs from A088934 are n=22,31,52,87,89,98,118,127,... %e A089294 a(22)=13 because 22 can be represented as -13^2+11^2+7^2+5^2-2^2. %e A089294 The corresponding representation with the minimum number of terms is %e A089294 22=19^2-13^2-11^2-7^2 (A088934(22)=19, A088910(22)=4 terms) %Y A089294 The positions of the records in this sequence are given in A089295. Cf. A088910, A088934. %K A089294 nonn %O A089294 0,1 %A A089294 _W. Edwin Clark_ Nov 06 2003