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 A143850 #31 Jul 11 2022 16:04:39
%S A143850 9,17,25,29,37,49,65,73,85,89,97,109,121,145,149,157,169,185,193,205,
%T A143850 229,241,265,269,277,289,325,349,361,409,425,433,445,481,485,493,505,
%U A143850 529,541,565,601,625,661,685,689,697,709,745,769,829,841,845,853,865
%N A143850 Numbers of the form (p^2 + q^2)/2, for odd primes p and q.
%C A143850 The primes in this sequence are listed in A103739.
%C A143850 a(n) mod 4 = 1. See A227697 for related sequence. - _Richard R. Forberg_, Sep 22 2013
%C A143850 The squares of primes in this sequence form the subsequence A001248 \ {4}. - _Bernard Schott_, Jul 09 2022
%H A143850 T. D. Noe, <a href="/A143850/b143850.txt">Table of n, a(n) for n = 1..1000</a>
%t A143850 Take[Union[Total[#]/2&/@(Tuples[Prime[Range[2,20]],2]^2)],60] (* _Harvey P. Dale_, Dec 28 2014 *)
%o A143850 (PARI) list(lim)=my(v=List(), p2); lim\=1; if(lim<9, lim=8); forprime(p=3, sqrtint(2*lim-9), p2=p^2; forprime(q=3, min(sqrtint(2*lim-p2), p), listput(v, (p2+q^2)/2))); Set(v) \\ _Charles R Greathouse IV_, Feb 14 2017
%Y A143850 Cf. A001248, A045636, A103739, A227697.
%Y A143850 Cf. A075892 (a subsequence).
%K A143850 nonn
%O A143850 1,1
%A A143850 _T. D. Noe_, Sep 03 2008