The On-Line Encyclopedia of Integer Sequences (OEIS)

A248501 revision #20

A248501

Numbers m that are coprime to floor(m/16).

1, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 50, 52, 53, 55, 56, 58, 59, 61, 62, 65, 67, 69, 71, 73, 75, 77, 79, 81, 82, 83, 84, 86, 87, 88, 89, 91, 92, 93, 94, 97, 101, 103, 107, 109, 113, 114, 115

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OFFSET

1,2

COMMENTS

Definition of 'being coprime' and special-case conventions are as in Wikipedia. In particular, when m<16 then floor(m/16)=0, and zero is coprime only to 1. The complementary sequence is A248502.

LINKS

Stanislav Sykora, Table of n, a(n) for n = 1..20000

Stanislav Sykora, PARI/GP scripts: Vector utilities

Wikipedia, Coprime integers

FORMULA

gcd(a(n),floor(a(n)/16)) = 1.

EXAMPLE

1 is a member because gcd(1,0)=1.

2 is not, because gcd(2,0)=2.

129 is a member because 129 and floor(129/16)=8.

PROG

(PARI) RT16Coprime(n)=gcd(n, n\16)==1; \\ The condition