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 A082073 #14 Mar 26 2020 18:01:05 %S A082073 8,4,12,8,4,12,8,12,16,8,4,8,4,24,12,8,16,8,12,4,32,4,8,16,12,8,4,12, %T A082073 20,4,20,12,4,20,16,8,4,8,12,12,16,8,4,48,12,20,16,12,8,16,8,12,4,24, %U A082073 12,8,12,4,24,8,24,24,4,8,4,24,12,12,8,24,4,20,4,48,8,4,12,24,20,12,4,8,12 %N A082073 First difference set of primes with 4k+1 form: A002144. %C A082073 a(n) is divisible by 4, for all n. %H A082073 Charles R Greathouse IV, <a href="/A082073/b082073.txt">Table of n, a(n) for n = 1..10000</a> %F A082073 a(n) = A002144(n+1) - A002144(n). %e A082073 first and second 4k+1 primes are 5 and 13, so a(1)=13-5=8; %t A082073 k=0; m=4; r=1; Do[s=Mod[Prime[n], m]; If[Equal[s, r], rp=ep; k=k+1; ep=Prime[n]; Print[(ep-rp)]; ], {n, 1, 1000}] %t A082073 Differences[Select[Prime[Range[200]],Mod[#,4]==1&]] (* _Harvey P. Dale_, Feb 05 2020 *) %o A082073 (PARI) p=5;forprime(q=7,1e3,if(q%4==1,print1(q-p", ");p=q)) \\ _Charles R Greathouse IV_, May 13 2012 %Y A082073 Cf. A002144, A002145, A082074, A082075, A082076. %K A082073 nonn,easy %O A082073 1,1 %A A082073 _Labos Elemer_, Apr 07 2003