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.

A002796 Numbers that are divisible by each nonzero digit.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15, 20, 22, 24, 30, 33, 36, 40, 44, 48, 50, 55, 60, 66, 70, 77, 80, 88, 90, 99, 100, 101, 102, 104, 105, 110, 111, 112, 115, 120, 122, 124, 126, 128, 132, 135, 140, 144, 150, 155, 162, 168, 175, 184, 200, 202, 204, 208, 210, 212
Offset: 1

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Comments

If n is a member so is 10*n. Also all repunits are members. - Robert G. Wilson v, Apr 12 2015
The repdigits are also members because they're always the repunit number of the same length multiplied by the digit being repeated. - Eric Fox, Sep 02 2019
The number of terms < 10^k: 9, 32, 137, 751, 4577, 29950, 207197, 1495637, ... . - Robert G. Wilson v, Apr 13 2015
Includes all multiples of 2520. - Robert Israel, Apr 15 2015
For n >= 10: A067458(a(n)) = 0. - Reinhard Zumkeller, Sep 24 2015

References

  • Lindon, Visible factor numbers, J. Rec. Math., 1 (1968), 217.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A171492 (complement).
Cf. A067458.

Programs

  • Haskell
    import Data.List (nub, sort); import Data.Char (digitToInt)
    a002796 n = a002796_list !! (n-1)
    a002796_list = filter f [1..] where
       f x = all ((== 0) . mod x) ds where
         ds = map digitToInt (if c == '0' then cs else cs')
         cs'@(c:cs) = nub $ sort $ show x
    -- Reinhard Zumkeller, Jan 01 2014
    
  • Magma
    sol:=[];for k in [1..220] do a:=Set(Intseq(k)) diff {0}; if #[c:c in a|IsIntegral(k/c)] eq #a then; Append(~sol,k); end if; end for; sol; // Marius A. Burtea, Sep 09 2019
    
  • Maple
    select(t -> t mod ilcm(op(convert(convert(t,base,10),set) minus {0})) = 0, [$1..1000]); # Robert Israel, Apr 15 2015
  • Mathematica
    dQ[n_]:=Module[{nzidn=DeleteCases[IntegerDigits[n],0]},And@@Divisible[n, nzidn]]; Select[Range[250],dQ] (* Harvey P. Dale, Dec 13 2011 *)
  • PARI
    is(n)=my(v=vecsort(eval(Vec(Str(n))),,8));for(i=1+(v[1]==0), #v, if(n%v[i],return(0)));1 \\ Charles R Greathouse IV, Apr 17 2012
    
  • Python
    A002796_list = []
    for i in range(1,10**5):
        for d in set(str(i)):
            if d != '0' and i % int(d):
                break
        else:
            A002796_list.append(i) # Chai Wah Wu, Mar 26 2021

Formula

a(n) ~ 2520*n. - Charles R Greathouse IV, Feb 13 2017

Extensions

More terms from Henry Bottomley, Jun 06 2000