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 A102821 #4 Jul 06 2014 17:54:59 %S A102821 2,4,5,8,9,13,14,15,19,20,23,27,28,30,35,36,37,38,39,46,49,56,57,67, %T A102821 68,69,71,81,83,86,93,94,96,98,107,108,109,111,112,113,114,124,128, %U A102821 138,139,142,144,155,156,157,158,159,160,161,162,173,178,182,192,195,196,199 %N A102821 Numbers n for which the square excess of n-th prime is prime. %e A102821 7 - 2^2 = 3 is the square excess (see A056892) of 7 and it is prime. 7 is the 4th prime, so 4 is in the sequence. %t A102821 Select[Range[200],PrimeQ[Prime[#]-Floor[Sqrt[Prime[#]]]^2]&] (* _Harvey P. Dale_, Jul 06 2014 *) %Y A102821 Cf. A056892. %K A102821 easy,nonn %O A102821 0,1 %A A102821 _Olaf Voß_, Feb 27 2005