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 A082377 #15 Dec 05 2024 09:26:54 %S A082377 1,2,3,4,5,7,8,9,11,13,16,17,18,19,23,24,25,27,29,31,32,36,37,40,41, %T A082377 43,45,47,48,49,50,53,54,56,59,61,63,64,67,71,72,73,75,79,80,81,83,88, %U A082377 89,96,97,98,99,100,101,103,104,107,108,109,112,113,117,120,121,125,127 %N A082377 Numbers k such that rad(k) - phi(k) <= 1, where rad = A007947 and phi = A000010. %C A082377 Includes all the prime numbers. - _Amiram Eldar_, Dec 05 2024 %H A082377 Amiram Eldar, <a href="/A082377/b082377.txt">Table of n, a(n) for n = 1..10000</a> %o A082377 (PARI) is(n)=my(f=factor(n)[,1],r=prod(i=1,#f,f[i])); r-n/r*prod(i=1,#f,f[i]-1)<=1 \\ _Charles R Greathouse IV_, Feb 21 2013 %Y A082377 Cf. A000010 (phi), A007947 (rad). %K A082377 nonn %O A082377 1,2 %A A082377 _Reinhard Zumkeller_, Apr 10 2003