A077377 - OEIS

%I #7 Feb 14 2018 12:03:28

%S 1,2,3,5,6,7,10,11,13,14,15,17,19,21,22,23,26,29,30,31,33,34,35,37,38,

%T 39,41,42,43,46,47,51,53,55,57,58,59,61,62,65,66,67,69,70,71,73,74,77,

%U 78,79,82,83,85,86,87,89,91,93,94,95,97,101,103,105,107,109,110,111,113

%N Squarefree numbers whose external digits form a squarefree number.

%H Charles R Greathouse IV, <a href="/A077377/b077377.txt">Table of n, a(n) for n = 1..10000</a>

%o (PARI) list(lim)=my(v=List(),n,t); for(d=0,logint(lim\=1,10), t=10^d; forsquarefree(k=t,min(10*t-1,lim), if(issquarefree(k[1]\t*10 + k[1]%10), listput(v,k[1])))); Vec(v) \\ _Charles R Greathouse IV_, Feb 14 2018

%Y Cf. A077376, A077378, A077379, A077380.

%K base,easy,nonn

%O 1,2

%A _Amarnath Murthy_, Nov 06 2002

%E a(1) inserted by _Charles R Greathouse IV_, Feb 14 2018