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 A260212 #6 Jul 19 2015 14:19:34 %S A260212 48,9800,31211,32798,48373,59534,63000,118579,373827,488187,629693, %T A260212 830464,1294298,3815174,8388223,9235520,9516680,9841094,11121382, %U A260212 12708359,14325848,15407171,18966023,19890624,24737542,28140000,29320000,29445038,34032190,38033406 %N A260212 Integers n such that core(n), core(n+1), core(n+2) are smaller than n^(1/2) where core(n) is A007913(n), the squarefree part of n. %C A260212 Up to 10^12, the only quadruplet starts at 160150258573. %H A260212 Giovanni Resta, <a href="/A260212/b260212.txt">Table of n, a(n) for n = 1..461</a> (terms < 10^12) %e A260212 48 is a term since core(48) = 3, core(49) = 1 and core(50) = 2 are all smaller than the square root of 48. %t A260212 core[n_] := Times@@ ((#[[1]] ^ Mod[#[[2]], 2])& /@ FactorInteger@ n); Select[ Range[10^6], core[#]^2 < # && core[#+1]^2 < # && core[#+2]^2 < # &] %Y A260212 Cf. A007913, A254625. %K A260212 nonn %O A260212 1,1 %A A260212 _Giovanni Resta_, Jul 19 2015