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 A064522 #11 Feb 19 2024 10:33:58 %S A064522 1,2,4,6,8,12,16,20,24,32,36,40,48,64,72,80,84,96,120,128,144,160,168, %T A064522 192,216,240,256,272,288,312,320,336,384,400,432,440,480,504,512,544, %U A064522 576,624,640,672,720,768,800,864,880,960,1008,1024,1088,1152,1248,1280 %N A064522 For an integer n with prime factorization p1*p2*p3* ... *pn let n* = (p1-1)*(p2-1)*(p3-1)* ... *(pn-1) (A003958); sequence gives n such that n is divisible by n*. %H A064522 Harry J. Smith, <a href="/A064522/b064522.txt">Table of n, a(n) for n = 1..1000</a> %o A064522 (PARI) nsm(n)= { local(f,p=1); f=factor(n); for(i=1, matsize(f)[1], p*=(f[i, 1] - 1)^f[i, 2]); return(p) } { n=0; for (m=1, 10^9, if (m%nsm(m) == 0, write("b064522.txt", n++, " ", m); if (n==1000, break)) ) } \\ _Harry J. Smith_, Sep 17 2009 %Y A064522 Cf. A064476, A003958. %K A064522 nonn %O A064522 1,2 %A A064522 _Vladeta Jovovic_, Oct 07 2001