A250042 Numbers n such that m = floor(n/9) is coprime to n and, if nonzero, m is also a term of the sequence.

1, 9, 10, 11, 12, 13, 14, 15, 16, 17, 82, 83, 85, 86, 88, 89, 91, 93, 97, 100, 101, 102, 103, 104, 105, 106, 107, 109, 113, 115, 118, 119, 120, 121, 122, 123, 124, 125, 127, 129, 131, 136, 137, 139, 142, 143, 145, 147, 149, 151, 154, 155, 156, 157, 158

Offset

1,2

Comments

See the comments in A250040 which all apply, except for the setting of the base, b=9. 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 the link
(PARI) is_rtc(n, b=9) =  {while (((m=gcd(n\b, n)) == 1), if (m == 0, return (1)); if ((n=n\b) == 0, return (1)); ); return (0); } \\ Michel Marcus, Jan 18 2015

Crossrefs

Cf. A250040 (b=10), A250043.

Other lists of right-truncatable numbers with the property RTC(b): A250036 (b=4), A250038 (b=16), A250044 (b=8), A250046 (b=7), A250048 (b=6), A250050 (b=5).

Sequence in context: A182362 A023392 A060009 * A115843 A058365 A162789

Adjacent sequences: A250039 A250040 A250041 * A250043 A250044 A250045

Keyword

nonn,base

Author

Stanislav Sykora, Jan 15 2015

Status

approved