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.

A062043 Positive numbers whose product of digits is 10 times their sum.

Original entry on oeis.org

459, 495, 549, 594, 945, 954, 1566, 1656, 1665, 2259, 2295, 2355, 2529, 2535, 2553, 2592, 2925, 2952, 3255, 3525, 3552, 5166, 5229, 5235, 5253, 5292, 5325, 5352, 5523, 5532, 5616, 5661, 5922, 6156, 6165, 6516, 6561, 6615, 6651, 9225, 9252, 9522
Offset: 1

Views

Author

Amarnath Murthy, Jun 28 2001

Keywords

Comments

A subsequence of A011535 as each term must include the digit 5. - Chai Wah Wu, Dec 09 2015

Examples

			594 belongs to the sequence as (5*9*4)/(5+9+4) = 180/18 = 10.
		

Crossrefs

Programs

  • Maple
    filter:= proc(t) local L;
      L:= convert(t,base,10);
      convert(L,`*`) = 10*convert(L,`+`)
    end proc:
    select(filter, [$1..10^5]); # Robert Israel, Sep 11 2022
  • Mathematica
    Select[Range[10000], Times @@ IntegerDigits[ # ] == 10 Plus @@ IntegerDigits[ # ] &] (* Tanya Khovanova, Dec 25 2006 *)
  • PARI
    isok(n) = my(d=digits(n)); vecprod(d)==10*vecsum(d) \\ Mohammed Yaseen, Sep 11 2022
    
  • Python
    from math import prod
    def ok(n): d = list(map(int, str(n))); return prod(d) == 10*sum(d)
    print([k for k in range(1, 9999) if ok(k)]) # Michael S. Branicky, Sep 11 2022

Extensions

More terms from Harvey P. Dale and Larry Reeves (larryr(AT)acm.org), Jul 06 2001