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.

A182183 Numbers k such that the divisors of k are divisible by all digits of their divisors.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 15, 22, 24, 33, 44, 55, 66, 77, 88, 99, 132, 264, 1111111111111111111, 2222222222222222222, 3333333333333333333, 4444444444444444444, 5555555555555555555, 6666666666666666666, 7777777777777777777, 8888888888888888888
Offset: 1

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Author

Jaroslav Krizek, Apr 17 2012

Keywords

Comments

Subsequence of A209933 (numbers that are divisible by all digits of their divisors).
All divisors of numbers in this sequence are also in the sequence.
The primitive elements of this sequence are A116692. No member of this sequence is divisible by a prime outside this sequence. - Charles R Greathouse IV, Apr 17 2012

Examples

			Number 48 with divisors 1, 2, 3, 4, 6, 8, 12, 16, 24, 48 is not in the sequence because 6 is not a divisor of 16.
		

Crossrefs

Subsequence of A034838. A116692 is a subsequence.
Cf. A209933.
Cf. A027751.
Cf. A027751.

Programs

  • Haskell
    import Data.List ((\\))
    a182183 n = a182183_list !! (n-1)
    a182183_list = f a209933_list [1] where
       f (x:xs) ys =
         if null (a027751_row x \\ ys) then x : f xs (x : ys) else f xs ys
    -- Reinhard Zumkeller, Apr 19 2012
  • PARI
    all(n)=my(v=vecsort(eval(Vec(Str(n))),,8)); if(v[1]==0, return(0)); for(i=1,#v,if(n%v[i],return(0)));1
    is(n)=fordiv(n,d,if(!all(d),return(0)));1 \\ Charles R Greathouse IV, Apr 17 2012
    

Extensions

a(24)-a(31) from Charles R Greathouse IV, Apr 17 2012