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 A139811 #16 Jan 08 2019 18:08:49 %S A139811 19,43,47,61,73,79,83,89,109,113,137,139,157,167,181,197,199,211,229, %T A139811 233,239,241,271,281,283,293,313,317,353,359,383,389,401,439,443,449, %U A139811 463,467,503,509,521,523 %N A139811 Primes prime(n) such that prime(n)^2 - prime(n + 2)*prime(n - 2) < 0. %t A139811 Prime[Select[Range[100], Prime[#]^2 - Prime[# + 2]Prime[# - 2] < 0 &]] %t A139811 Select[Partition[Prime[Range[120]],5,1],#[[3]]^2-#[[5]] #[[1]]<0&][[All,3]] (* _Harvey P. Dale_, Jan 08 2019 *) %Y A139811 Cf. A130903. %K A139811 nonn,easy %O A139811 1,1 %A A139811 _Roger L. Bagula_ and _Gary W. Adamson_, May 23 2008 %E A139811 Edited by _N. J. A. Sloane_, May 23 2008