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 A075403 #10 Dec 05 2013 19:55:38 %S A075403 2,1,5,28,10,48,13,15,65,160,58,80,106,32,162,91,94,188,70,127,62,304, %T A075403 201,120,394,103,141,244,382,455,301,380,521,700,625,212,721,611,681, %U A075403 979,277,815,1201,1275,569,4588,558,2331,5113,1704,1337,2551,2101 %N A075403 Smallest k such that the difference between the k-th triangular number and the following prime is equal to n. %C A075403 Index of the first occurrence of n in A075402. %H A075403 Donovan Johnson, <a href="/A075403/b075403.txt">Table of n, a(n) for n = 0..500</a> %o A075403 (PARI) for(n=1,100,f=0:for(k=1,50000,if(nextprime(k*(k+1)/2)-k*(k+1)/2==n,f=k:break)):print1(f",")) %Y A075403 Cf. A075402. %K A075403 nonn %O A075403 0,1 %A A075403 _Amarnath Murthy_, Sep 23 2002 %E A075403 Corrected and extended by _Ralf Stephan_, Mar 19 2003