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
Offset: 0
Keywords
Examples
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.
Crossrefs
Cf. A070298.
Programs
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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","))
Extensions
Corrected and extended by Ralf Stephan, Mar 22 2003
Comments