A275450 Numbers n such that primorial(n) contains n as a string of digits.

3, 9, 21, 27, 34, 35, 36, 37, 38, 39, 41, 42, 43, 44, 45, 46, 50, 51, 52, 53, 56, 57, 58, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 70, 73, 74, 75, 76, 77, 79, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 103, 107

Offset: 1

Author

Ivan N. Ianakiev, Jul 28 2016

Keywords

• base
• easy
• nonn

Examples

			Primorial(3) equals 30, which contains 3, therefore 3 is in the sequence.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A002110 (primorial numbers), A275451.

Programs

Maple

count:= 0:
P:= 2; p:= 2;
for n from 2 while count < 1000 do
  p:= nextprime(p);
  P:= P*p;
  if StringTools:-Search(sprintf("%d",n),sprintf("%d",P))<>0 then
     count:= count+1;
     A[count]:= n;
  fi
od:
seq(A[i],i=1..count); # Robert Israel, Jul 29 2016

Mathematica

primorial[n_]:=Product[Prime[i],{i,1,n}];
Select[Range@500,StringContainsQ[ToString[primorial[#]],ToString[#]]&]

Perl

use ntheory ":all"; my @a275450 = grep { index(pn_primorial($),$) >= 0 } 1 .. 1000; say "@a275450"; # Dana Jacobsen, Aug 09 2016

Formula

A275451(a(n)) > 0.