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 A134604 #12 Apr 09 2025 15:12:32
%S A134604 119,161,351,595,721,845,959,1045,1081,1241,1323,1375,1547,1792,1855,
%T A134604 2457,2645,2737,3281,3367,3509,3887,3995,4347,4625,4655,4681,5376,
%U A134604 5795,6545,6615,6643,6993,7505,7705,7803,7889,8019,9295,9625,10557,11845
%N A134604 Numbers (excluding primes and powers of primes) such that the square mean of their prime factors is a prime (where the square mean of c and d is sqrt((c^2+d^2)/2)).
%C A134604 Numbers included in A134601, but not in A025475. a(1)=119 is the minimal number with this property.
%H A134604 Hieronymus Fischer, <a href="/A134604/b134604.txt">Table of n, a(n) for n = 1..10000</a>
%e A134604 a(2) = 161, since 161 = 7*23 and sqrt((7^2+23^2)/2) = sqrt(289)=17 is a prime.
%e A134604 a(10183) = 114383711 = 13*83*227*467 and sqrt((13^2+83^2+227^2+467^2)/4) = sqrt(69169) = 263 is a prime.
%t A134604 f[{a_,b_}]:=Table[a,b];Select[Range[2,11845],!PrimePowerQ[#]&&PrimeQ[ RootMeanSquare[f/@FactorInteger[#]//Flatten] ]&] (* _James C. McMahon_, Apr 09 2025 *)
%Y A134604 Cf. A001597, A025475, A134333, A134344, A134376.
%Y A134604 Cf. A134600, A134602, A134608, A134611, A134617, A134619, A134621.
%K A134604 nonn
%O A134604 1,1
%A A134604 _Hieronymus Fischer_, Nov 11 2007
%E A134604 Minor edits by _Hieronymus Fischer_, Apr 22 2013