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 A109311 #8 Jul 05 2018 11:00:54
%S A109311 6,17,58,78,89,122,187,219,229,278,313,353,367,552,589,966,1162,1264,
%T A109311 1530,1637,1745,1928,2343,2443,2540,2648,2789,3649,3778,3811,3900,
%U A109311 4143,4191,5038,5228,5280,5426,5466,6169,6613,6718,7161,8225,9342,9607
%N A109311 Numbers n such that sum of n-th and (n+1)-st semiprimes is a square=q^2.
%F A109311 sp(n)+sp(n+1)=q^2, sp(n)=n-th semiprime.
%e A109311 6 is ok because sp(6)=15, sp(7)=21, 15+21=36=6^2, sp(n)=A001358(n)=n-th semiprime.
%t A109311 Position[Partition[Select[Range[40000],PrimeOmega[#]==2&],2,1],_?(IntegerQ[ Sqrt[Total[#]]]&),1,Heads->False]//Flatten (* _Harvey P. Dale_, Jul 05 2018 *)
%o A109311 (PARI) lista(nn) = {vec = vector(nn, i, i); sp = select(i->(bigomega(i)==2), vec); for (i = 1, #sp-1, if (issquare(sp[i+1]+sp[i]), print1(i, ", ")););} \\ _Michel Marcus_, Oct 06 2013
%Y A109311 Values of q: A109312. Cf. A001358 = semiprimes, A092191 = numbers n such that sum of n-th and (n+1)-st semiprimes is a semiprime.
%K A109311 nonn
%O A109311 1,1
%A A109311 _Zak Seidov_, Jun 27 2005
%E A109311 More terms from _Michel Marcus_, Oct 06 2013