A215671 Number of integers less than 10^n which are not divisible by any of the first n primes.

5, 33, 266, 2285, 20779, 191808, 1805253, 17102403, 163588197, 1579472234, 15285215141, 148721012165, 1450936704024, 14171939899753, 138704092635854, 1360870342842311, 13378047438110802, 131587351850270160, 1296233615241467193, 12779768037591930031

Offset

1,1

Links

Table of n, a(n) for n=1..20.

Example

a(1) = 5 because there are 5 numbers below 10^1 {1, 3, 5, 7, 9} not divisible by prime(1) = 2.

Maple

for n from 1 to 20 do:ni:=0:for m from 1 to 10^n -1 do:i:=0:for q from 1 to n do:p:=ithprime(q):if irem(m, p)=0 then i:=1:else fi:od:if i=0 then ni:=ni+1:else fi:od: printf ( "%d %d \n", n, ni):od:

Crossrefs

Cf. A000040.

Sequence in context: A135075 A269820 A302075 * A049377 A325153 A129890

Adjacent sequences: A215668 A215669 A215670 * A215672 A215673 A215674

Keyword

nonn

Author

Michel Lagneau, Aug 20 2012

Status

approved