A250043 - OEIS

A250043

Numbers n such that m = floor(n/9) is not coprime to n and, if nonzero, m is also a term of the sequence.

2, 3, 4, 5, 6, 7, 8, 18, 20, 22, 24, 26, 27, 30, 33, 36, 38, 40, 42, 44, 45, 50, 54, 56, 57, 58, 60, 62, 63, 70, 72, 74, 76, 78, 80, 162, 164, 165, 166, 168, 170, 180, 182, 184, 185, 186, 188, 198, 200, 202, 204, 206, 216, 218, 219, 220, 222, 224, 234, 236

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OFFSET

1,1

COMMENTS

See the comments in A250041 which all apply, except for the setting of the base, b=9. 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=9) = {while (((m=gcd(n\b, n)) != 1), if (m == 0, return (1)); n = n\b; ); return (0); } \\ Michel Marcus, Jan 17 2015

CROSSREFS

Cf. A250041 (b=10), A250042.

Other lists of right-truncatable numbers with the property RTNC(b): A005823 (b=3), A250037 (b=4), A250039 (b=16), A250045 (b=8), A250047 (b=7), A250049 (b=6), A250051 (b=5).

Sequence in context: A204928 A171723 A039050 * A366103 A260354 A114799

Adjacent sequences: A250040 A250041 A250042 * A250044 A250045 A250046

KEYWORD

nonn,base

AUTHOR

Stanislav Sykora, Jan 15 2015

STATUS

approved