A250050 - OEIS

A250050

Numbers n such that m = floor(n/5) is coprime to n and, if nonzero, m is also a term of the sequence.

1, 5, 6, 7, 8, 9, 26, 27, 28, 29, 31, 36, 37, 38, 39, 41, 43, 46, 47, 49, 131, 133, 136, 137, 139, 141, 143, 146, 147, 148, 149, 156, 157, 158, 159, 181, 186, 187, 188, 189, 191, 193, 196, 197, 199, 206, 207, 208, 209, 216, 217, 218, 219, 231, 233, 236, 237

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

OFFSET

1,2

COMMENTS

See the comments in A250040 which all apply, except for the setting of the base, b=5. In particular, they define the property RTC(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 A250040 for b=5

(PARI) is_rtc(n, b=5) = {while (((m=gcd(n\b, n)) == 1), if (m == 0, return (1)); if ((n=n\b) == 0, return (1)); ); return (0); } \\ Michel Marcus, Jan 31 2015

CROSSREFS

Cf. A250040 (b=10), A250047.

Other lists of right-truncatable numbers with the property RTC(b): A250036 (b=4), A250038 (b=16), A250042 (b=9), A250044 (b=8), A250046 (b=7), A250048 (b=6).

Sequence in context: A102717 A015977 A294239 * A051052 A377265 A119368

Adjacent sequences: A250047 A250048 A250049 * A250051 A250052 A250053

KEYWORD

nonn,base

AUTHOR

Stanislav Sykora, Jan 31 2015

STATUS

approved