cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-4 of 4 results.

A244356 Numbers n such that n and n+1 are not divisible by any of their nonzero digits.

Original entry on oeis.org

37, 46, 53, 56, 57, 58, 67, 68, 73, 78, 86, 97, 307, 337, 346, 358, 373, 376, 379, 388, 397, 406, 429, 433, 446, 457, 466, 469, 473, 477, 478, 489, 493, 498, 506, 507, 508, 538, 553, 556, 557, 558, 577, 578, 586, 587, 588, 596, 597, 598, 646, 656, 657, 658, 667, 668, 669
Offset: 1

Views

Author

Derek Orr, Jun 26 2014

Keywords

Comments

This is a subsequence of A038772.
All numbers end in a 3, 6, 7, 8, or 9.

Examples

			37 is not divisible by 3 or 7 and 38 is not divisible by 3 or 8. Thus 37 is a member of this sequence.

Links

Crossrefs

Cf. A038772, A237766.

Programs

  • Maple
    filter:= proc(n) local L;
  L:= convert(convert(n,base,10), set) minus {0};
  not ormap(t -> n mod t = 0, L)
end proc:
B:= select(filter, {$1..1000}):
sort(convert(B intersect map(`-`,B,1), list)); # Robert Israel, Dec 08 2019
  • Python
    def a(n):
  for i in range(10**3):
    tot = 0
    for k in range(i,i+n):
      c = 0
      for b in str(k):
        if b != '0':
          if k%int(b)!=0:
            c += 1
      if c == len(str(k))-str(k).count('0'):
        tot += 1
    if tot == n:
      print(i,end=', ')
a(2)

A244357 Numbers n such that n, n+1, and n+2 are not divisible by any of their nonzero digits.

Original entry on oeis.org

56, 57, 67, 477, 506, 507, 556, 557, 577, 586, 587, 596, 597, 656, 657, 667, 668, 697, 757, 758, 778, 787, 788, 857, 858, 866, 867, 868, 877, 897, 956, 957, 976, 977, 978, 4077, 4097, 4457, 4477, 4497, 4657, 4677, 4757, 4857, 4897, 4997, 5056, 5057, 5066, 5067, 5077, 5096
Offset: 1

Views

Author

Derek Orr, Jun 26 2014

Keywords

Comments

This is a subsequence of A244356.
All numbers end in a 6, 7, or 8.

Examples

			56, 57, and 58 are not divisible by their digits. Thus, 56 is a member of this sequence.

Links

Crossrefs

Cf. A038772, A244356, A237766.

Programs

  • Mathematica
    SequencePosition[Table[If[NoneTrue[n/Select[IntegerDigits[n],#>0&],IntegerQ], 1,0],{n,5100}],{1,1,1}][[All,1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 15 2018 *)
  • Python
    def a(n):
  for i in range(10**4):
    tot = 0
    for k in range(i,i+n):
      c = 0
      for b in str(k):
        if b != '0':
          if k%int(b)!=0:
            c += 1
      if c == len(str(k))-str(k).count('0'):
        tot += 1
    if tot == n:
      print(i,end=', ')
a(3)

A244358 Numbers k such that k, k+1, k+2, and k+3 are not divisible by any of their nonzero digits.

Original entry on oeis.org

56, 506, 556, 586, 596, 656, 667, 757, 787, 857, 866, 867, 956, 976, 977, 5056, 5066, 5096, 5506, 5666, 5756, 5776, 5876, 5906, 5986, 5996, 6056, 6067, 6506, 6697, 6986, 7057, 7556, 7576, 7597, 7757, 7786, 7787, 7876, 7897, 7906, 7976, 7996, 8066, 8067, 8506, 8596, 8666, 8697
Offset: 1

Views

Author

Derek Orr, Jun 26 2014

Keywords

Comments

This is a subsequence of A244357.
All numbers end in a 6 or 7.

Examples

			56, 57, 58, and 59 are not divisible by any of their digits. Thus, 56 is a member of this sequence.

Links

Crossrefs

Cf. A038772, A237766, A244357.

Programs

  • Mathematica
    SequencePosition[Table[If[NoneTrue[n/(IntegerDigits[n]/.(0->Nothing)),IntegerQ],1,0],{n,9000}],{1,1,1,1}][[;;,1]] (* Harvey P. Dale, Jun 06 2025 *)
  • Python
    def a(n):
  for i in range(10**4):
    tot = 0
    for k in range(i,i+n):
      c = 0
      for b in str(k):
        if b != '0':
          if k%int(b)!=0:
            c += 1
      if c == len(str(k))-str(k).count('0'):
        tot += 1
    if tot == n:
      print(i,end=', ')
a(4)

A244359 Numbers n such that n, n+1, n+2, n+3, and n+4 are not divisible by any of their nonzero digits.

Original entry on oeis.org

866, 976, 7786, 8066, 8786, 8986, 9976, 70786, 77786, 79976, 80066, 80986, 87866, 89066, 89986, 98786, 99866, 99976, 700786, 707786, 709976, 770786, 778786, 778996, 780866, 788986, 789986, 799786, 799976, 800066, 800986, 809986, 879986, 887986, 888986, 889786, 890066, 890786, 890986
Offset: 1

Views

Author

Derek Orr, Jun 26 2014

Keywords

Comments

This is a subsequence of A244358.
All numbers end in a 6 and every number contains some combination of {6,7,8,9,0}.
There are no consecutive terms in this sequence. See A237766.

Examples

			866, 867, 868, 869 and 870 are not divisible by any of their nonzero digits. Thus 866 is a member of this sequence.

Crossrefs

Cf. A038772, A244358, A237766.

Programs

  • Mathematica
    div[n_]:=Module[{nzd=Select[IntegerDigits[n],#!=0&]},NoneTrue[n/nzd, IntegerQ]]; SequencePosition[Table[If[div[n],1,0],{n,900000}],{1,1,1,1,1}][[All,1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 11 2018 *)
  • Python
    def a(n):
  for i in range(10**4):
    tot = 0
    for k in range(i,i+n):
      c = 0
      for b in str(k):
        if b != '0':
          if k%int(b)!=0:
            c += 1
      if c == len(str(k))-str(k).count('0'):
        tot += 1
    if tot == n:
      print(i,end=', ')
a(5)
Showing 1-4 of 4 results.

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