

A248499


Numbers m that are coprime to A059995(m): floor(m/10).


6



1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 23, 25, 27, 29, 31, 32, 34, 35, 37, 38, 41, 43, 45, 47, 49, 51, 52, 53, 54, 56, 57, 58, 59, 61, 65, 67, 71, 72, 73, 74, 75, 76, 78, 79, 81, 83, 85, 87, 89, 91, 92, 94, 95, 97, 98, 101, 103, 107, 109, 111, 112
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OFFSET

1,2


COMMENTS

Definition of 'being coprime' and specialcase conventions are as in Wikipedia. In particular, when m<10 then floor(m/10)=0, and zero is coprime only to 1. The complementary sequence is A248500. Note: The first 57 terms a(n) coincide with A069715, but the two sequences are different.
The limit mean density of these numbers exists and equals 1223/2100 = A250031(10)/A250033(10).  Stanislav Sykora, Dec 08 2014


LINKS

Stanislav Sykora, Table of n, a(n) for n = 1..20000
S. Sykora, On some number densities related to coprimes, Stan's Library, Vol.V, Nov 2014, DOI: 10.3247/SL5Math14.005.
Wikipedia, Coprime integers


FORMULA

gcd(a(n),floor(a(n)/10)) = 1.


EXAMPLE

1 is a member because gcd(1,0)=1.
123 is not a member because gcd(123,12)=3.
165 is a member because 165 and 16 are coprime.


MATHEMATICA

Select[ Range@ 120, GCD[#, Floor[#/10]] == 1 &] (* Robert G. Wilson v, Oct 22 2014 *)


PROG

(PARI) a=vector(20000);
i=n=0; while(i++, if(gcd(i, i\10)==1, a[n++]=i; if(n==#a, break))); a


CROSSREFS

Cf. A059995, A248500, A248501, A248502, A250031, A250033.
Sequence in context: A256556 A063662 A069715 * A008716 A011531 A257946
Adjacent sequences: A248496 A248497 A248498 * A248500 A248501 A248502


KEYWORD

nonn,base,easy


AUTHOR

Stanislav Sykora, Oct 07 2014


STATUS

approved



