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 A327592 #29 Oct 18 2019 01:03:57 %S A327592 397,68219,87881,316531,430487,440653,639701,691813,732497,982981, %T A327592 1145773,1226683,1288337,1291223,1537751,1563943,1756663,1913803, %U A327592 2043397,2134589,2143391,2317097,2366789,2528833,3047311,3107597,3261523,3678869,3884389,4143397 %N A327592 Smallest prime (p) of six consecutive primes (p,q,r,u,v,w) for which the conic section discriminant (Delta) is a perfect square. %C A327592 Delta = pqr + 2uvw - pu^2 - qv^2 - rw^2 for the general conic section px^2 + qy^2 + rz^2 + 2uyz + 2vxz + 2wxy = 0. %C A327592 Perfect squares of this form are quite rare, representing approximately 0.0048% of possible Delta values using consecutive prime number coefficients. (First 4 million primes tested.) %H A327592 Giovanni Resta, <a href="/A327592/b327592.txt">Table of n, a(n) for n = 1..10000</a> (first 192 terms from Philip Mizzi) %e A327592 48 = sqrt(2304) = pqr + 2uvw - pu^2 - qv^2 - rw^2 for (p,q,r,u,v,w) = (440653,440669,440677,440681,440683,440711), which are consecutive primes. Hence, 440653 is a member of the sequence. %t A327592 f[{p_, q_, r_, u_, v_, w_}] := p q r + 2 u v w - p u^2 - q v^2 - r w^2; First /@ Select[Partition[ Prime@ Range@ 300000, 6, 1], IntegerQ@ Sqrt@ f@ # &] (* _Giovanni Resta_, Sep 30 2019 *) %o A327592 (PARI) chk(nn) = {forprime (p=1, nn, my(q = nextprime(p+1), r = nextprime(q+1), u = nextprime(r+1), v = nextprime(u+1), w = nextprime(v+1)); if (issquare(p*q*r + 2*u*v*w - p*u^2 - q*v^2 - r*w^2), print1(p, ", ")););} \\ _Michel Marcus_, Sep 30 2019 %Y A327592 Cf. A000040. %K A327592 nonn %O A327592 1,1 %A A327592 _Philip Mizzi_, Sep 18 2019