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 A085931 #10 Dec 15 2017 17:44:30 %S A085931 2,4,12,17,23,39,48,58,69,95,109,124,140,157,195,215,236,258,281,305, %T A085931 357,384,412,441,471,502,534,602,637,673,710,748,787,827,868,954,998, %U A085931 1043,1089,1136,1184,1233,1283,1334,1440,1494,1549,1605,1662,1720,1779 %N A085931 Leading diagonal of A085930. %H A085931 Gheorghe Coserea, <a href="/A085931/b085931.txt">Table of n, a(n) for n = 1..10000</a> %H A085931 T. Forbes, <a href="http://anthony.d.forbes.googlepages.com/adf.htm">Prime k-tuplets</a> %o A085931 (PARI) %o A085931 a(n) = my(x = (sqrtint(1+8*n)-1)\2); (x+n)*(x+n+1)/2 - n; %o A085931 vector(51, n, a(n)) \\ _Gheorghe Coserea_, Mar 25 2016 %Y A085931 Cf. A085930. %K A085931 easy,nonn %O A085931 1,1 %A A085931 _Jason Earls_ and _Amarnath Murthy_, Jul 14 2003 %E A085931 Offset corrected by _Gheorghe Coserea_, Mar 25 2016