A239220 - OEIS

%I #21 Jan 16 2022 13:29:50

%S 27,343,6859,24389,50653,79507,97336,205379,300763,456533,493039,

%T 636056,704969,2048383,2924207,3307949,3869893,4330747,4657463,

%U 4826809,5735339,6539203,7645373,7880599,23639903,26730899,28934443,30664297,33698267,38272753,42508549

%N Cubes that are not divisible by any of their nonzero digits.

%C Intersection of A000578 and A038772.

%C Sequence is infinite because it contains (2*10^k + 3)^3, for k>1 and k not of the form 6*h + 2. - _Giovanni Resta_, Mar 13 2014

%H Lars Blomberg, <a href="/A239220/b239220.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A239219(n)^3. - _Michel Marcus_, Mar 19 2014

%e 50653 is in the sequence because 37^3 = 50653 is not divisible by 3, 5 or 6.

%t ndnzdQ[n_]:=NoneTrue[n/Select[IntegerDigits[n],#!=0&],IntegerQ]; Select[ Range[ 400]^3,ndnzdQ] (* _Harvey P. Dale_, Jan 16 2022 *)

%o (PARI) isOK(n) = my(v=vecsort(digits(n^3), , 8)); for(i=1+(v[1]==0), #v, if(n^3%v[i]==0, return(0))); 1

%o s=[]; for(n=1, 1000, if(isOK(n), s=concat(s, n^3))); s

%Y Cf. A239219, A239221, A239222.

%Y Cf. A000578, A038772.

%K nonn,base

%O 1,1

%A _Colin Barker_, Mar 12 2014