A250051 Numbers n such that m = floor(n/5) is not coprime to n and, if nonzero, m is also a term of the sequence.

2, 3, 4, 10, 12, 14, 15, 18, 20, 22, 24, 50, 52, 54, 60, 62, 63, 64, 70, 72, 74, 75, 78, 90, 92, 93, 94, 100, 102, 104, 110, 112, 114, 120, 122, 123, 124, 250, 252, 254, 260, 262, 264, 270, 272, 273, 274, 300, 302, 303, 304, 310, 312, 314, 315, 318

Offset

1,1

Comments

See the comments in A250041 which all apply, except for the setting of the base, b=5. 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 A250041 for b=5
(PARI) is_rtnc(n, b=5) = {while (((m=gcd(n\b, n)) != 1), if (m == 0, return (1)); n = n\b; ); return (0); } \\ Michel Marcus, Jan 31 2015

Crossrefs

Cf. A250041 (b=10), A250046.

Other lists of right-truncatable numbers with the property RTNC(b):

A005823 (b=3), A250037 (b=4), A250039 (b=16), A250043 (b=9), A250045 (b=8), A250047 (b=7), A250049 (b=6).

Sequence in context: A085701 A051627 A023725 * A076079 A229593 A196007

Adjacent sequences: A250048 A250049 A250050 * A250052 A250053 A250054

Keyword

nonn,base

Author

Stanislav Sykora, Jan 31 2015

Status

approved