A250046 - OEIS

A250046

Numbers n such that m = floor(n/7) is coprime to n and, if nonzero, m is also a term of the sequence.

1, 7, 8, 9, 10, 11, 12, 13, 50, 51, 52, 53, 54, 55, 57, 59, 61, 64, 65, 67, 68, 71, 73, 78, 79, 80, 81, 82, 83, 85, 89, 92, 93, 94, 95, 96, 97, 351, 353, 358, 359, 361, 362, 365, 367, 369, 372, 373, 374, 375, 376, 377, 379, 383, 386, 387, 388, 389, 391, 400

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OFFSET

1,2

COMMENTS

See the comments in A250040 which all apply, except for the setting of the base, b=7. 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=7) = {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), A250047.

Other lists of right-truncatable numbers with the property RTC(b): A250036 (b=4), A250038 (b=16), A250042 (b=9), A250044 (b=8), A250048 (b=6), A250050 (b=5).

Sequence in context: A182308 A023388 A065808 * A062947 A194345 A363492

Adjacent sequences: A250043 A250044 A250045 * A250047 A250048 A250049

KEYWORD

nonn,base

AUTHOR

Stanislav Sykora, Jan 15 2015

STATUS

approved