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.

A193772 Nonnegative integers whose digital difference is 0.

Original entry on oeis.org

0, 11, 22, 33, 44, 55, 66, 77, 88, 99, 101, 110, 202, 211, 220, 303, 312, 321, 330, 404, 413, 422, 431, 440, 505, 514, 523, 532, 541, 550, 606, 615, 624, 633, 642, 651, 660, 707, 716, 725, 734, 743, 752, 761, 770, 808, 817, 826, 835, 844, 853, 862, 871, 880
Offset: 1

Views

Author

Dario Piazzalunga, Jan 02 2013

Keywords

Comments

The subsequence of multiples of 11 begins: 0, 11, 22, 33, 44, 55, 66, 77, 88, 99, 110, 220, 330, 440...
The subsequence of primes begins: 11, 101, 211, 431, 523, 541, 743, 761, 853, ... (see A156307).

Crossrefs

Programs

  • Maple
    V:= proc(n,s) # n-digits numbers with sum of digits s
         option remember; local i,k;
         `union`(seq(seq(map(t -> i*10^(n-1) + t, procname(k,s-i)),k=1..n-1),i=1..min(s,9)))
    end proc:
    for s from 0 to 9 do V(1,s) := {s} od:
    f:= proc(n) local s,k;
       `union`(seq(seq(map(t -> s*10^(n-1) + t, V(k,s)), k=1..n-1),s=1..9))
    end proc:
    sort(convert(`union`(seq(f(d),d=1..4)),list)); # Robert Israel, Nov 14 2024
  • Mathematica
    fQ[n_] := Module[{d = IntegerDigits[n]}, d[[1]] == Total[Rest[d]]]; Select[Range[0, 1000], fQ] (* T. D. Noe, Jan 02 2013 *)

Formula

If decimal expansion of n is x1 x2 ... xk then x1 - x2 - ... - xk = 0.

Extensions

Definition edited by Michel Marcus, Oct 26 2014