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.

A248040 Numbers n such that n*digsum(n) contains the same distinct digits as n.

Original entry on oeis.org

1, 10, 100, 109, 190, 208, 280, 307, 370, 406, 450, 460, 505, 550, 604, 640, 703, 730, 802, 820, 901, 910, 1000, 1009, 1018, 1027, 1036, 1045, 1054, 1063, 1072, 1081, 1090, 1108, 1168, 1180, 1207, 1270, 1286, 1306, 1360, 1405, 1450, 1504, 1540, 1603, 1630, 1702, 1720, 1726, 1801
Offset: 1

Views

Author

Derek Orr, Sep 30 2014

Keywords

Comments

10^k is a subsequence for k >= 0. Thus this sequence is infinite.

Crossrefs

Cf. A007953 (sum of digits), A011557 (powers of 10).
Cf. A247888 (similar, with n + product of digits), A247887 (similar, with n + digsum).

Programs

  • Maple
    filter:= proc(n) local L,s,d;
      L:= convert(n,base,10);
      d:= convert(L,set);
      s:= convert(L,`+`);
      evalb(convert(convert(n*s,base,10),set)=d)
    end proc:
    select(filter, [$1..2000]); # Robert Israel, Mar 06 2018
  • PARI
    for(n=1,10^4,d=digits(n);if(vecsort(d,,8)==vecsort(digits(n*sumdigits(n)),,8),print1(n,", ")))