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 1-9 of 9 results.

A187398 Numbers divisible by at least three of their digits, all different and >1.

Original entry on oeis.org

248, 264, 324, 384, 396, 432, 624, 648, 672, 728, 735, 784, 824, 864, 936, 1236, 1248, 1296, 1326, 1362, 1368, 1395, 1632, 1692, 1764, 1824, 1926, 1935, 1962, 2048, 2064, 2136, 2184, 2196, 2248, 2304, 2316, 2328, 2340, 2346, 2364, 2376, 2384, 2394, 2408, 2436, 2448, 2460, 2480, 2488, 2496, 2540, 2568, 2584, 2604, 2634, 2640, 2648, 2664, 2688, 2730, 2736, 2744, 2784, 2824, 2832, 2840, 2848, 2856, 2864, 2916, 2934, 2964, 2984, 3024, 3048, 3096, 3126, 3162, 3168
Offset: 1

Views

Author

Zak Seidov, Mar 10 2011

Keywords

Comments

Asymptotic density 19/63 = 0.301.... - Charles R Greathouse IV, Mar 11 2011

Crossrefs

Subsequence of A187516 (numbers divisible by at least two of their digits, different and >1).

Programs

  • Mathematica
    numdig = 3; Select[Range[3168], Length[(u = Union[Select[IntegerDigits[#], #1 > 1 &]])] >= numdig && Plus @@ (Boole@Divisible[#, u]) >= numdig &] (* Amiram Eldar, Aug 30 2020 *)

A187238 Numbers divisible by at least four of their digits, different and >1.

Original entry on oeis.org

2364, 2436, 3264, 3276, 3492, 3624, 3648, 3864, 3924, 4236, 4368, 4392, 4632, 4872, 4896, 4932, 4968, 6324, 6384, 6432, 6984, 8496, 8736, 9324, 9432, 9648, 9864, 12384, 12648, 12768, 12864, 13248, 13824, 13896, 13968, 14328, 14728, 14832, 16248, 16824, 17248, 18264
Offset: 1

Views

Author

Zak Seidov, Mar 11 2011

Keywords

Comments

There are 14594 terms < 10^6.
Asymptotic density 10/63 = 0.158.... - Charles R Greathouse IV, Mar 11 2011

Crossrefs

Programs

  • Mathematica
    numdig = 4; Select[Range[23640], Length[(u = Union[Select[IntegerDigits[#], #1 > 1 &]])] >= numdig && Plus @@ (Boole@Divisible[#, u]) >= numdig &] (* Amiram Eldar, Aug 30 2020 *)

A187533 Numbers divisible by at least five of their digits, different and >1.

Original entry on oeis.org

27384, 29736, 36792, 37296, 37926, 38472, 46872, 73248, 73962, 78624, 79632, 84672, 92736, 123648, 123864, 123984, 124368, 126384, 129384, 132648, 132864, 132984, 134928, 136248, 136824, 138264, 138624, 139248, 139824, 142368, 143928, 146328, 146832, 148392, 148632, 149328, 149832, 162384, 163248, 163824, 164328, 164832, 167328, 167832, 168432, 172368, 183264, 183624, 184392, 184632, 186432, 189432, 192384, 193248, 193824, 194328
Offset: 1

Views

Author

Zak Seidov, Mar 11 2011

Keywords

Comments

There are 11936 terms < 4*10^6.
Asymptotic density 97/1260 = 0.0769.... - Charles R Greathouse IV, Mar 11 2011

Crossrefs

Subsequence of A187238.

Programs

  • Mathematica
    numdig = 5; Select[Range[194328], Length[(u = Union[Select[IntegerDigits[#], #1 > 1 &]])] >= numdig && Plus @@ (Boole@Divisible[#, u]) >= numdig &] (* Amiram Eldar, Aug 30 2020 *)

A187534 Numbers divisible by at least six of their digits, different and >1.

Original entry on oeis.org

243768, 247968, 248976, 297864, 364728, 367248, 376824, 427896, 428736, 432768, 469728, 478296, 478632, 483672, 623784, 627984, 634872, 689472, 732648, 742896, 746928, 762384, 768432, 789264, 796824, 824376, 836472, 873264, 897624, 927864, 976248, 978264, 1289736, 1293768, 1369872, 1372896, 1376928, 1382976, 1679328, 1679832
Offset: 1

Views

Author

Zak Seidov, Mar 11 2011

Keywords

Comments

There are 1437 terms < 10^7.
Asymptotic density 1/35 = 0.0285.... - Charles R Greathouse IV, Mar 11 2011

Crossrefs

Subsequence of A187533.

Programs

  • Mathematica
    numdig = 6; Select[Range[1679832], Length[(u = Union[Select[IntegerDigits[#], #1 > 1 &]])] >= numdig && Plus @@ (Boole@Divisible[#, u]) >= numdig &] (* Amiram Eldar, Aug 30 2020 *)
    Select[Range[2*10^5,168*10^4],Length[Select[#/Union[DeleteCases[IntegerDigits[#],1]],IntegerQ]]>5&]//Quiet (* Harvey P. Dale, Mar 18 2025 *)

A187551 Numbers divisible by at least seven of their digits, different and >1.

Original entry on oeis.org

23469768, 23579640, 23594760, 23674896, 23684976, 23687496, 23745960, 23746968, 23769648, 23796864, 23876496, 23897664, 23947560, 23957640, 23976540, 24367896, 24375960, 24376968, 24539760, 24679368, 24687936, 24753960, 24783696, 24869376, 24876936, 25497360, 25639740, 25749360, 25793460, 25967340
Offset: 1

Views

Author

Zak Seidov, Mar 11 2011

Keywords

Comments

There are 708 terms < 10^8.
Asymptotic density 1/180 = 0.00555.... - Charles R Greathouse IV, Mar 11 2011

Crossrefs

Subsequence of A187534.

Programs

  • Mathematica
    numdig = 7; Select[Range[25967340], Length[(u = Union[Select[IntegerDigits[#], #1 > 1 &]])] >= numdig && Plus @@ (Boole@Divisible[#, u]) >= numdig &] (* Amiram Eldar, Aug 30 2020 *)

A187565 Numbers divisible by at least eight of their digits, different and >1.

Original entry on oeis.org

1234759680, 1234857960, 1234895760, 1234958760, 1235487960, 1235679480, 1235976840, 1236795840, 1237569480, 1237589640, 1237594680, 1237695480, 1237894560, 1238549760, 1238574960, 1238597640, 1238975640, 1239547680, 1239567840, 1239756840, 1239784560, 1239847560, 1239857640, 1243579680, 1243589760, 1243879560, 1243957680, 1245378960, 1245973680, 1245983760
Offset: 1

Views

Author

Zak Seidov, Mar 11 2011

Keywords

Comments

First 11460 terms are pandigital numbers (A050278).
Asymptotic density 1/2520 = 0.000396.... - Charles R Greathouse IV, Mar 11 2011
11460 terms up to 10^10, 299275 terms up to 10^11, 6224794 terms up to 10^12. - Charles R Greathouse IV, Mar 11 2011

Crossrefs

Subsequence of A187551 (numbers divisible by at least seven ...).

Programs

  • Mathematica
    numdig = 8; Select[Range[1245983760], Length[(u = Union[Select[IntegerDigits[#], #1 > 1 &]])] >= numdig && Plus @@ (Boole@Divisible[#, u]) >= numdig &] (* Amiram Eldar, Aug 30 2020 *)
  • PARI
    s(n) = my(res=Set(digits(n)));select(x->x>1,res)
    is(n) = my(d=s(n));if(#d < 8, return(0)); sum(i=1, #d, n%d[i]==0) >= 8 \\ David A. Corneth, Aug 30 2020

A139138 Numbers divisible by at least two of their digits.

Original entry on oeis.org

11, 12, 15, 22, 24, 33, 36, 44, 48, 55, 66, 77, 88, 99, 101, 102, 104, 105, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 128, 131, 132, 135, 138, 140, 141, 142, 144, 145, 147, 148, 150, 151, 152, 153, 155, 156, 161, 162
Offset: 1

Views

Author

Jonathan Vos Post, Jun 05 2008

Keywords

Comments

Digits need not be distinct. This may be considered row 2 of an infinite array whose 1st row is A038770. Each such row is a subset of the ones above it.

Crossrefs

Programs

  • Mathematica
    fQ[n_] := Count[Mod[n, Flatten[IntegerDigits[n] /. {0 -> {}}]], 0] > 1; Select[ Range@ 170, fQ] (* Robert G. Wilson v, Jun 23 2014 *)
    Select[Range[200],Count[Divisible[#,Select[IntegerDigits[#], #>0&]], True]>1&] (* Harvey P. Dale, Dec 16 2015 *)
  • Python
    from sympy import factorint
    def ok(n): return sum(1 for d in map(int, str(n)) if d > 0 and n%d == 0) > 1
    print([k for k in range(163) if ok(k)]) # Michael S. Branicky, Nov 12 2021

Extensions

More terms from Alvin Hoover Belt, Apr 06 2009
Own omission (140) fixed by Alvin Hoover Belt, Apr 18 2009

A185186 Numbers divisible by at least one of their digits other than 1.

Original entry on oeis.org

2, 3, 4, 5, 6, 7, 8, 9, 12, 15, 20, 22, 24, 25, 26, 28, 30, 32, 33, 35, 36, 39, 40, 42, 44, 45, 48, 50, 52, 55, 60, 62, 63, 64, 65, 66, 70, 72, 75, 77, 80, 82, 84, 85, 88, 90, 92, 93, 95, 96, 99, 102, 104, 105, 112, 115, 120, 122, 123, 124, 125, 126, 128, 132
Offset: 1

Views

Author

Zak Seidov, Mar 11 2011

Keywords

Comments

The only primes in the sequence are 2, 3, 5, 7. No repunits are eligible.
Also, an interesting class of non-eligible integers consists of some powers of 2, 3 and 7:
"2, 4, 8-less" powers of 2, 2^m = 1, 16, 65536 with m = 0, 4, 16 (a subsequence of A034293);
"3, 9-less" powers of 3, 3^m = {1, 27, 81, 177147, 1162261467}, with m = {0, 3, 4, 11, 19} (a subsequence of A131629);
"seven-less" powers of 7, 7^m, with m = 0, 2, 3, 4, 7, 16, 22, 24, 39 (see 6th row of A136291 Array read by rows: each row is a sequence of numbers k such that n^k does not contain the digit n).
Asymptotic density 27/35 = 0.771... - Charles R Greathouse IV, Mar 11 2011
The asymptotic density of numbers having a prime digit is 1 for each prime digit. The asymptotic density of numbers being divisible by 2, 3, 5 or 7 is -Sum_{d|210, d>1}((-1)^omega(d) / d) = 27/35. Also, the asymptotic density of numbers divisible by the first n primes is r(n) where r(1) = 1/2 and r(n) = r(n - 1) + (1 - r(n - 1)) / prime(n). - David A. Corneth, May 28 2017

Crossrefs

Programs

  • Mathematica
    digDivQ[n_] := AnyTrue[IntegerDigits[n], # > 1 && Mod[n, #] == 0 &]; Select[Range[200], digDivQ] (* Giovanni Resta, May 27 2017 *)
  • PARI
    is(n) = my(d = vecsort(digits(n), , 8), t = 1); while(t<=#d&&d[t] < 2, t++); sum(i=t, #d, n%d[i]==0) > 0 \\ David A. Corneth, May 27 2017

Extensions

Name edited by Alonso del Arte, May 16 2017

A187584 Least number divisible by at least n of its digits, different and > 1.

Original entry on oeis.org

2, 24, 248, 2364, 27384, 243768, 23469768, 1234759680
Offset: 1

Views

Author

Zak Seidov, Mar 11 2011

Keywords

Comments

a(1)=2=A185186(1), a(2)=24=A187516(1),
a(3)=248=A187398(1), a(4)=2364=A187238(1),
a(5)=27384=A187533(1), a(6)=243768=A187534(1),
a(7)=23469768=A187551(1), a(8)=1234759680=A187565(1).

Crossrefs

Programs

  • Mathematica
    divQ[m_, n_] := Length[(u = Union[Select[IntegerDigits[m], # > 1 &]])] >= n && Plus @@ (Boole@Divisible[m, u]) >= n; a[n_] := Module[{k = 1}, While[! divQ[k, n], k++]; k]; Array[a, 8] (* Amiram Eldar, Aug 30 2020 *)
  • Python
    def c(n): return len(set(d for d in str(n) if d>'1' and n%int(d)==0))
    def a(n):
      m = 2*10**(n-1)
      while c(m) < n: m += 1
      return m
    print([a(n) for n in range(1, 7)]) # Michael S. Branicky, Feb 24 2021

Extensions

a(8) corrected by David A. Corneth, Aug 30 2020
Showing 1-9 of 9 results.