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 A110284 #28 Sep 08 2022 08:45:19 %S A110284 9,25,49,121,169,289,625,841,961,1225,1681,1849,2401,3025,4489,5929, %T A110284 6889,10201,11881,13225,14161,15625,17689,19321,20449,22801,24025, %U A110284 24649,25921,32041,32761,39601,41209,44521,48841,49729,55225,57121,69169 %N A110284 Squares of the form 4p - 3, where p is a prime. %C A110284 Also: squares of the form 2*s-3, where s is a semiprime, A107317. - _Franklin T. Adams-Watters_, Jun 28 2010 %C A110284 Squares are less dense then primes and easy to generate so it's faster to check squares if they are of the required form than to check if primes are of the required form. - _David A. Corneth_, Oct 15 2018 %H A110284 David A. Corneth, <a href="/A110284/b110284.txt">Table of n, a(n) for n = 1..16289</a> (First 1316 terms by Marius A. Burtea, terms < 10^11) %F A110284 a(n) = 4*A002383(n) - 3 = A088503(n-1)^2. %t A110284 Select[ 4Prime[ Range[2000]] - 3, IntegerQ[ Sqrt[ # ]] &] (* _Robert G. Wilson v_, Sep 20 2005 *) %o A110284 (PARI) isok(n) = issquare(n) && (p=(n+3)/4) && (frac(p)==0) && isprime(p); \\ _Michel Marcus_, Oct 15 2018 %o A110284 (PARI) upto(n) = my(res = List()); forstep(i = 3, sqrtint(n), 2, if(isprime((i^2+3)/4), listput(res, i^2))); res \\ _David A. Corneth_, Oct 15 2018 %o A110284 (Magma) [4*p - 3: p in PrimesUpTo(10^5)|IsSquare (4*p - 3)]; // _Vincenzo Librandi_, Oct 17 2018 %Y A110284 Cf. A002383, A002384, A088503, A001358. %K A110284 nonn %O A110284 1,1 %A A110284 _Giovanni Teofilatto_, Sep 07 2005 %E A110284 Extended by _Ray Chandler_, Sep 07 2005