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 A119382 #9 Sep 16 2015 11:54:30
%S A119382 12,19,59,92,112,115,140,211,233,253,261,268,276,285,291,294,301,322,
%T A119382 352,358,369,389,407,417,473,500,542,598,612,624,714,718,723,742,819,
%U A119382 933,939,994,998,1016,1098,1119,1263,1299,1312,1400,1414,1418,1422,1449
%N A119382 Indices j of prime numbers p(j) such that (p(j-1) + p(j+2)) / p(j) = 2.
%H A119382 Harvey P. Dale, <a href="/A119382/b119382.txt">Table of n, a(n) for n = 1..3000</a>
%e A119382 a(1)=12 because the 11th prime 31 plus the 14th prime 43 divided by the 12th prime 37 equals 2.
%t A119382 Select[Range[2, 1500], (Prime[ # - 1] + Prime[ # + 2])/(Prime[ # ]) == 2 &] (* _Stefan Steinerberger_, Jul 26 2006 *)
%t A119382 Module[{c},Off[Part::partd]; c=Flatten[Position[Partition[Prime[ Range[ 1500]],4,1],_?((#[[1]]+#[[4]])/#[[2]]==2&)]]+1;On[Part::partd];c] (* _Harvey P. Dale_, Jan 01 2013 *)
%K A119382 nonn
%O A119382 1,1
%A A119382 _Axel Harvey_, Jul 25 2006
%E A119382 More terms from _Stefan Steinerberger_, Jul 26 2006