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 A105174 #17 Dec 27 2019 11:55:03 %S A105174 8,15,23,24,71,80,104,128,159,216,231,264,288,303,336,344,455,495,528, %T A105174 543,560,608,624,680,744,816,840,879,896,1016,1104,1311,1415,1440, %U A105174 1464,1520,1584,1599,1751,1871,1896,1920,1976,2015,2016,2055,2088,2103,2175 %N A105174 Numbers k such that k*(k+1)/4 - 1 and k*(k+1)/4 + 1 are twin primes. %C A105174 The twin primes are = (sum of numbers from 1 to k)/2 -1 and +1. %H A105174 Amiram Eldar, <a href="/A105174/b105174.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Harvey P. Dale) %e A105174 8*9/4=18, 17 and 19 twin primes so a(1)=8 %e A105174 15*16/4=60, 59 and 61 twin primes so a(2)=15 %t A105174 Select[Range[2200],AllTrue[(#(#+1))/4+{1,-1},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Aug 01 2015 *) %Y A105174 Cf. A001097, A001359, A006512, A165966. %K A105174 nonn %O A105174 1,1 %A A105174 _Pierre CAMI_, Apr 11 2005 %E A105174 More terms from _Zak Seidov_, Oct 07 2009