A250047 -id:A250047 - cp's OEIS frontend

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

Offset: 1

Stanislav Sykora, Jan 15 2015

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).

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

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).

PARI
```
See the link
```

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

A250037 Numbers n such that m = floor(n/4) is not coprime to n and, if nonzero, m is also a term of the sequence.

Original entry on oeis.org

2, 3, 8, 10, 12, 15, 32, 34, 40, 42, 48, 50, 51, 60, 63, 128, 130, 136, 138, 160, 162, 168, 170, 171, 192, 194, 195, 200, 202, 204, 207, 240, 242, 243, 252, 255, 512, 514, 520, 522, 544, 546, 552, 554, 555, 640, 642, 648, 650, 651, 672, 674, 675, 680, 682

Offset: 1

Stanislav Sykora, Dec 07 2014

See the comments in A250041 which all apply, except for the setting of the base, b=4. In particular, they define the property RTNC(b).

If x =12*k+j, 0 <= j <= 11, then x is in the sequence iff either j is in {0,2,3} and 3*k is in the sequence, or j is in {4,6} and 3*k+1 is in the sequence, or j is in {8,10} and 3*k+2 is in the sequence. - Robert Israel, Dec 22 2014

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

Cf. A250036, A250041.
Other lists of right-truncatable numbers with the property RTNC(b):
A005823 (b=3), A250039 (b=16), A250041 (b=10), A250043 (b=9), A250045 (b=8), A250047 (b=7), A250049 (b=6), A250051 (b=5).

S:= {}:
for n from 1 to 1000 do
  m:= floor(n/4);
  if igcd(m,n) = 1 then next fi;
  if m > 0 and not member(m,S) then next fi;
  S:= S union {n}
od:
S; # if using Maple 11 or earlier, uncomment the next line
# sort(convert(S,list)); # Robert Israel, Dec 22 2014

PARI
```
See the link.
```

is_rtnc(n, b=4) = {while (((m=gcd(n\b, n)) != 1), if (m == 0, return (1)); n = n\b; ); return (0); } \\ Michel Marcus, Jan 22 2015

A250039 Numbers n such that m = floor(n/16) is not coprime to n and, if nonzero, m is also a term of the sequence.

Original entry on oeis.org

2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 32, 34, 36, 38, 40, 42, 44, 46, 48, 51, 54, 57, 60, 63, 64, 66, 68, 70, 72, 74, 76, 78, 80, 85, 90, 95, 96, 98, 99, 100, 102, 104, 105, 106, 108, 110, 111, 112, 119, 126, 128, 130, 132, 134, 136, 138, 140, 142

Offset: 1

Stanislav Sykora, Dec 07 2014

See the comments in A250041 which all apply, except for the setting of the base, b=16. In particular, they define the property RTNC(b).

This list is an infinite subset of A248502 with which it shares the first 111 entries.

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

Cf. A248502, A250038, A250041.

Other lists of right-truncatable numbers with the property RTNC(b): A005823 (b=3), A250037 (b=4), A250041 (b=10), A250043 (b=9), A250045 (b=8), A250047 (b=7), A250049 (b=6), A250051 (b=5).

PARI
```
See the link.
```

is_rtnc(n, b=16) = {while (((m=gcd(n\b, n)) != 1), if (m == 0, return (1)); n = n\b; ); return (0); } \\ Michel Marcus, Jan 29 2015

A250041 Numbers n such that m = floor(n/10) is not coprime to n and, if nonzero, m is also a term of the sequence.

Original entry on oeis.org

2, 3, 4, 5, 6, 7, 8, 9, 20, 22, 24, 26, 28, 30, 33, 36, 39, 40, 42, 44, 46, 48, 50, 55, 60, 62, 63, 64, 66, 68, 69, 70, 77, 80, 82, 84, 86, 88, 90, 93, 96, 99, 200, 202, 204, 205, 206, 208, 220, 222, 224, 226, 228, 240, 242, 243, 244, 246, 248, 249, 260, 262

Offset: 1

Stanislav Sykora, Dec 07 2014

Equivalent definition 1: Assuming a base b (in this case b=10), let us say that a positive integer k has the property RTNC(b) when m=floor(k/b) is not coprime to k, i.e., gcd(k,m)>1. Then k belongs to this sorted list if (i) it has the property RTNC(b) and (ii) m is either 0 or belongs also to the list.
Equivalent definition 2: Every nonempty prefix of a(n) in base b has the property RTNC(b).
Notes: The acronym RTNC stands for 'Right-Truncated is Not Coprime' (negation of the property RTC defined in A250040). We could also say that a(n) are right-truncatable numbers with property RTNC(b).
This particular list is an infinite subset of A248500.

			243 is a member because (243,24), (24,2) and (2,0) are noncoprime pairs.
155 is not a member because gcd(15,1)=1.

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

Cf. A248500, A250040.

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), A250051 (b=5).

PARI
```
See the link.
```

is_rtnc(n, b=10) = {while (((m=gcd(n\b, n)) != 1), if (m == 0, return (1)); n = n\b; ); return (0); } \\ Michel Marcus, Jan 29 2015

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.

Original entry on oeis.org

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

Offset: 1

Stanislav Sykora, Jan 15 2015

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).

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

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).

PARI
```
See the link
```

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

A250045 Numbers n such that m = floor(n/8) is not coprime to n and, if nonzero, m is also a term of the sequence.

Original entry on oeis.org

2, 3, 4, 5, 6, 7, 16, 18, 20, 22, 24, 27, 30, 32, 34, 36, 38, 40, 45, 48, 50, 51, 52, 54, 56, 63, 128, 130, 132, 134, 144, 146, 147, 148, 150, 160, 162, 164, 165, 166, 176, 178, 180, 182, 192, 194, 195, 196, 198, 216, 219, 222, 240, 242, 243, 244, 245, 246

Offset: 1

Stanislav Sykora, Jan 15 2015

See the comments in A250041 which all apply, except for the setting of the base, b=8. In particular, they define the property RTNC(b).

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

Cf. A250041 (b=10), A250044.
Other lists of right-truncatable numbers with the property RTNC(b):
A005823 (b=3), A250037 (b=4), A250039 (b=16), A250043 (b=9), A250047 (b=7), A250049 (b=6), A250051 (b=5).

PARI
```
See the link
```

is_rtnc(n, b=8) = {while (((m=gcd(n\b, n)) != 1), if (m == 0, return (1)); n = n\b; ); return (0); } \\ Michel Marcus, Jan 22 2015

A250048 Numbers n such that m = floor(n/6) is coprime to n and, if nonzero, m is also a term of the sequence.

Original entry on oeis.org

1, 6, 7, 8, 9, 10, 11, 37, 41, 43, 44, 45, 46, 47, 49, 51, 53, 55, 56, 58, 59, 61, 63, 67, 68, 69, 70, 71, 223, 224, 225, 226, 227, 247, 248, 249, 250, 251, 259, 260, 261, 262, 263, 265, 267, 269, 271, 272, 274, 277, 279, 281, 283, 284, 285, 286, 287, 295

Offset: 1

Stanislav Sykora, Jan 31 2015

See the comments in A250040 which all apply, except for the setting of the base, b=6. In particular, they define the property RTC(b).

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

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), A250050 (b=5).

PARI
```
\\ See A250040 for b=6
```

is_rtc(n, b=6) =  {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

A250049 Numbers n such that m = floor(n/6) is not coprime to n and, if nonzero, m is also a term of the sequence.

Original entry on oeis.org

2, 3, 4, 5, 12, 14, 16, 18, 21, 24, 26, 28, 30, 35, 72, 74, 75, 76, 84, 86, 88, 96, 98, 100, 108, 110, 111, 112, 126, 129, 144, 146, 147, 148, 156, 158, 160, 168, 170, 172, 180, 182, 183, 184, 185, 210, 215, 432, 434, 435, 436, 444, 446, 448, 450, 453, 455

Offset: 1

Stanislav Sykora, Jan 31 2015

See the comments in A250041 which all apply, except for the setting of the base, b=6. In particular, they define the property RTNC(b).

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

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), A250051 (b=5).

PARI
```
\\ See A250041 for b=6
```

is_rtnc(n, b=6) = {while (((m=gcd(n\b, n)) != 1), if (m == 0, return (1)); n = n\b;); return (0); } \\ Michel Marcus, Jan 31 2015

A250050 Numbers n such that m = floor(n/5) is coprime to n and, if nonzero, m is also a term of the sequence.

Original entry on oeis.org

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

Offset: 1

Stanislav Sykora, Jan 31 2015

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).

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

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).

PARI
```
\\ See A250040 for b=5
```

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

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.

Original entry on oeis.org

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

Stanislav Sykora, Jan 31 2015

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).

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

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).

PARI
```
\\ See A250041 for b=5
```

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

cp's OEIS Frontend

A250046 Numbers n such that m = floor(n/7) is coprime to n and, if nonzero, m is also a term of the sequence.

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A250037 Numbers n such that m = floor(n/4) is not coprime to n and, if nonzero, m is also a term of the sequence.

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A250039 Numbers n such that m = floor(n/16) is not coprime to n and, if nonzero, m is also a term of the sequence.

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A250041 Numbers n such that m = floor(n/10) is not coprime to n and, if nonzero, m is also a term of the sequence.

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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.

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PARI

A250045 Numbers n such that m = floor(n/8) is not coprime to n and, if nonzero, m is also a term of the sequence.

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A250048 Numbers n such that m = floor(n/6) is coprime to n and, if nonzero, m is also a term of the sequence.

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A250049 Numbers n such that m = floor(n/6) is not coprime to n and, if nonzero, m is also a term of the sequence.

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