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 A069551 #11 Apr 06 2020 02:20:20 %S A069551 27,28,40,63,175,208,250,847,1053,1183,1216,1408,1656,2023,2527,3125, %T A069551 3703,4600,5887,6727,8125,8496,9016,9583,11767,12943,13851,15463, %U A069551 19116,19652,19663,22264,23600,24367,26047,26568,31096,31213,31423,31744 %N A069551 Numbers k such that the squarefree part of k equals A062799(k). %H A069551 Amiram Eldar, <a href="/A069551/b069551.txt">Table of n, a(n) for n = 1..1000</a> %F A069551 k such that A007913(k) = A062799(k). %t A069551 f[p_, e_] := If[OddQ[e], p, 1]; sqf[n_] := Times @@ (f @@@ FactorInteger[n]); imomega[n_] := DivisorSum[n, PrimeNu[#] &]; Select[Range[32000], sqf[#] == imomega[#] &] (* _Amiram Eldar_, Apr 06 2020 *) %o A069551 (PARI) for(n=1,50000,if(core(n)==sumdiv(n,d,omega(d)),print1(n,","))) %Y A069551 Cf. A007913, A062799. %K A069551 nonn %O A069551 1,1 %A A069551 _Benoit Cloitre_, Apr 17 2002