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 1-5 of 5 results.

A253647 Numbers n such that n^k is zeroless for k=0,...,6.

Original entry on oeis.org

1, 2, 3, 5, 6, 14, 17, 68, 76, 96, 188, 483, 518, 582, 736, 786, 1331, 1414, 3944, 4214, 6112, 6676, 8256, 8583, 8686, 9738, 15314, 15483, 33736, 44712, 48989, 61562, 71689, 78512, 93711, 121568, 187791, 239477, 292958, 315426, 545866, 763142, 792612, 1391739
Offset: 1

Views

Author

M. F. Hasler, Jan 07 2015

Keywords

Comments

Contains A124648 as a subsequence. Primes in this sequence are listed in A253646.
There are 55 terms below 10^7. Conjectured to be finite.

Crossrefs

Programs

  • Mathematica
    Select[Range[14*10^5],Count[Flatten[IntegerDigits/@(#^Range[ 0,6])],0] == 0&] (* Harvey P. Dale, Apr 29 2018 *)
  • PARI
    is_A253647(n,K=6)=!forstep(k=K,1,-1,vecmin(digits(n^k))||return)

A253645 Primes p such that p^k is zeroless for k=0,...,5.

Original entry on oeis.org

2, 3, 5, 13, 17, 23, 31, 137, 233, 337, 383, 719, 971, 1291, 1663, 1777, 3623, 6113, 12589, 15733, 15791, 17729, 22637, 44623, 48989, 61379, 65777, 72379, 82129, 91331, 99559, 132859, 133733, 163633, 226129, 239539, 346391, 352133, 394223, 415379, 428531, 485113, 518233, 546523
Offset: 1

Views

Author

Zak Seidov and M. F. Hasler, Jan 07 2015

Keywords

Comments

These are the primes in A253644. This is a subsequence of A253110 (k<=4) and contains A253646 (k <= 6) as a subsequence.
Motivated by A253646, i.e., the observation that many small primes satisfy this condition for k <= 5 (52 terms below 10^6) but only very few satisfy it for k <= 6 (only 2 terms between 20 and 2*10^9).

Crossrefs

Programs

  • Mathematica
    Select[Prime[Range[46000]],Count[Flatten[IntegerDigits/@(#^Range[5])],0] == 0&] (* Harvey P. Dale, Jan 13 2015 *)
  • PARI
    forprime(p=0,,forstep(k=5,1,-1,vecmin(digits(p^k))||next(2));print1(p","))

A252484 Numbers m such that m^k is zeroless for k=1,...,4.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 9, 11, 13, 14, 17, 21, 23, 24, 26, 27, 28, 31, 36, 39, 41, 46, 56, 58, 61, 62, 66, 68, 72, 76, 82, 83, 88, 91, 92, 96, 121, 122, 129, 137, 146, 154, 161, 162, 166, 167, 168, 183, 186, 188, 189, 211, 231, 233, 244, 256, 262, 264, 268, 277, 278, 289, 296, 337, 373, 374, 376, 382, 383
Offset: 1

Views

Author

M. F. Hasler, Jan 07 2015

Keywords

Comments

See A253110 for the primes in this sequence. See A253644 for the subsequence including k=5.

Crossrefs

Cf. A052382, A253643 (k <= 3), A253644 (k <= 5), A253645 (primes, k <= 5), A253647 (k <= 6), A253646 (primes, k <= 6), A124648 (k <= 7), A124649 (k <= 8).
Cf. A104264.

Programs

  • Maple
    filter:= proc(n)
    local j;
    for j from 0 to 4 do
      if has(convert(n^j,base,10),0) then return false fi
    od:
    true
    end proc:
    select(filter, [$1..1000]); # Robert Israel, Jan 15 2015
  • Mathematica
    Select[Range[400],Union[DigitCount[#^Range[4],10,0]]=={0}&] (* Harvey P. Dale, Aug 01 2020 *)
  • PARI
    is_A252484(n,K=4)=!forstep(k=K,1,-1,vecmin(digits(n^k))||return)

A253644 Numbers n such that n^k is zeroless for k=0,...,5.

Original entry on oeis.org

1, 2, 3, 5, 6, 13, 14, 17, 23, 24, 26, 31, 58, 62, 66, 68, 72, 76, 88, 96, 137, 168, 188, 233, 244, 262, 264, 296, 337, 376, 382, 383, 483, 488, 511, 514, 518, 519, 582, 628, 719, 736, 786, 816, 822, 928, 938, 971, 978, 1122, 1178, 1291, 1331, 1392, 1413, 1414, 1663, 1777
Offset: 1

Views

Author

M. F. Hasler, Jan 07 2015

Keywords

Comments

A subsequence of A252484 (analog for k <= 4) which contains A253647 (analog including k = 6) as a subsequence. Primes in this sequence are listed in A253645.
Conjectured to be finite.

Crossrefs

Programs

  • Maple
    filter:= proc(x)
      local k;
      for k from 1 to 5 do
        if has(convert(x^k,base,10),0) then return false fi
      od:
      true
    end proc:
    select(filter, [$1..10000]); # Robert Israel, Jan 07 2015
  • Mathematica
    Select[Range[2000],Count[Flatten[IntegerDigits/@(#^Range[5])],0]==0&] (* Harvey P. Dale, Jun 10 2017 *)
  • PARI
    is_A253644(n,K=5)=!forstep(k=K,1,-1,vecmin(digits(n^k))||return)

A253643 Numbers n such that n^k is zeroless for k=0,...,3.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 17, 18, 19, 21, 23, 24, 25, 26, 27, 28, 29, 31, 35, 36, 38, 39, 41, 44, 46, 54, 56, 57, 58, 61, 62, 65, 66, 68, 72, 75, 76, 77, 81, 82, 83, 85, 88, 91, 92, 96, 111, 113, 114, 119, 121, 122, 125, 129, 132, 133, 136, 137, 139, 146, 154, 156, 157, 158, 161
Offset: 1

Views

Author

M. F. Hasler, Mar 09 2015

Keywords

Comments

See A252484 for the subsequence of numbers having this property up to k=4.

Crossrefs

Cf. A052382, A252484 (k <= 4), A253644 (k <= 5), A253645 (primes, k <= 5), A253647 (k <= 6), A253646 (primes, k <= 6), A124648 (k <= 7), A124649 (k <= 8).
Cf. A104264.

Programs

  • Mathematica
    Select[Range[200],AllTrue[#^Range[3],DigitCount[#,10,0]==0&]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jul 15 2015 *)
  • PARI
    is_A253643(n,K=3)=!forstep(k=K,1,-1,vecmin(digits(n^k))||return)
    
  • Python
    for n in range(100):
      s1,s2,s3 = str(n),str(n**2),str(n**3)
      if s1.find('0') + s2.find('0') + s3.find('0') == -3:
        print(n,end=', ') # Derek Orr, Mar 09 2015
Showing 1-5 of 5 results.