A070297 - OEIS

A070297

Smallest number with n unrelated numbers (numbers which are neither coprime nor a divisor), or 0 if no such number exists.

3, 6, 0, 10, 15, 14, 21, 18, 35, 22, 33, 26, 39, 0, 65, 30, 36, 38, 57, 44, 95, 46, 63, 42, 115, 50, 64, 58, 87, 54, 75, 68, 155, 60, 99, 74, 111, 72, 185, 66, 117, 86, 129, 92, 215, 94, 141, 78, 235, 84, 105, 98, 100, 96, 265, 90, 135, 118, 147, 122, 183, 108

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OFFSET

0,1

COMMENTS

The 0's are only conjectures (search extended to 2000).

LINKS

Table of n, a(n) for n=0..61.

EXAMPLE

a(0) = 4, as 4 has no unrelated numbers less than it. a(5) = 14. The unrelated numbers pertaining to 14 are 4,6,8 10 and 12.

PROG

(PARI) for(n=0, 100, s=-1:k=2:while(s!=n&&k<2000, k=k+1:s=0:for(l=2, k-1, if((k%l>0)&&gcd(k, l)>1, s=s+1))): if(k==2000, k=0):print1(k", "))

CROSSREFS