A250045 - OEIS

A250045

Numbers n such that m = floor(n/8) is not coprime to n and, if nonzero, m is also a term of the sequence.

2, 3, 4, 5, 6, 7, 16, 18, 20, 22, 24, 27, 30, 32, 34, 36, 38, 40, 45, 48, 50, 51, 52, 54, 56, 63, 128, 130, 132, 134, 144, 146, 147, 148, 150, 160, 162, 164, 165, 166, 176, 178, 180, 182, 192, 194, 195, 196, 198, 216, 219, 222, 240, 242, 243, 244, 245, 246

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

See the comments in A250041 which all apply, except for the setting of the base, b=8. In particular, they define the property RTNC(b).

LINKS

Stanislav Sykora, Table of n, a(n) for n = 1..10000

Stanislav Sykora, PARI/GP scripts for genetic threads, with code and comments

Wikipedia, Coprime integers

PROG

(PARI) See the link

(PARI) is_rtnc(n, b=8) = {while (((m=gcd(n\b, n)) != 1), if (m == 0, return (1)); n = n\b; ); return (0); } \\ Michel Marcus, Jan 22 2015