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
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
Programs
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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.