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

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.

The asymptotic density of this sequence is A250031(16)/A250033(16) = 280817/480480 = 0.58445... . - Amiram Eldar, Nov 30 2024

Links

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

Wikipedia, Coprime integers.

Formula

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

Example

1 is a term because gcd(1,0) = 1.
2 is not a term because gcd(2,0) = 2.
129 is a term because 129 is coprime to floor(129/16) = 8.

Mathematica

Select[Range[120], CoprimeQ[#, Floor[#/16]]&] (* Harvey P. Dale, Mar 12 2023 *)

Prog

(PARI) a=vector(20000);
i=n=0; while(i++, if(gcd(i, i\16)==1, a[n++]=i; if(n==#a, break))); a

Crossrefs

Cf. A248499, A248500, A248502, A250031, A250033.

Sequence in context: A262460 A190582 A004457 * A115420 A250038 A296754

Adjacent sequences: A248498 A248499 A248500 * A248502 A248503 A248504

Keyword

nonn,base,easy

Author

Stanislav Sykora, Oct 07 2014

Status

approved