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 A173875 #12 Sep 08 2022 08:45:50 %S A173875 5,11,59,1439,2459,2819,3119,4079,4799,5399,5879,6899,7559,12539, %T A173875 13799,14159,16139,19379,25919,27239,28019,28499,29759,39119,40739, %U A173875 41519,42179,44159,44939,46919,53759,57119,60539,63599,64019,65579,66359 %N A173875 Primes p of the form a^2-b^2 and p*a-b is also prime (with b=prime and a=b+1). %H A173875 Vincenzo Librandi, <a href="/A173875/b173875.txt">Table of n, a(n) for n = 1..300</a> %F A173875 A005385 INTERSECT A048161. [_R. J. Mathar_, Mar 29 2010] %e A173875 p=11 is in this sequence because 6^2-5^2=11 and 11*6-5=61. %e A173875 4799 is in this sequence because 2400^2-2399^2=4799 and 4799*2400-2399=11515201. %t A173875 Select[Prime[Range[10000]], PrimeQ[(# - 1)/2] &&PrimeQ[ (#^2 + 1)/2] &] (* _Vincenzo Librandi_, Aug 21 2014 *) %o A173875 (Magma) [p: p in PrimesUpTo(10^5) | IsPrime((p-1) div 2) and IsPrime((p^2+1) div 2)]; // _Vincenzo Librandi_ Aug 21 2014 %K A173875 nonn %O A173875 1,1 %A A173875 _Vincenzo Librandi_, Mar 06 2010 %E A173875 Missing terms inserted and sequence extended by _R. J. Mathar_, Mar 29 2010