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.

A058906 Inconsummate numbers in base 11: no number is this multiple of the sum of its digits (in base 11).

Original entry on oeis.org

68, 70, 79, 80, 82, 92, 104, 200, 202, 212, 214, 224, 225, 248, 260, 314, 320, 332, 380, 392, 452, 458, 464, 490, 502, 508, 512, 513, 514, 518, 520, 524, 530, 562, 568, 574, 578, 579, 580, 584, 585, 590, 592, 595, 598, 599, 622, 628, 634, 635
Offset: 1

Views

Author

N. J. A. Sloane, Jan 09 2001

Keywords

Crossrefs

Programs

  • Maple
    digitsum := proc (n,b) local i; add(i,i=convert(n,base,b)) end; b := 11:N := 43922; L := []: for n from 1 to N do k := digitsum(n,b): if (n mod k)=0 then L := [op(L), n/k] fi: od: M := []: for i from 1 to 1000 do if not(member(i,L)) then M := [op(M),i] fi od: lprint(M);
  • Mathematica
    base = 11; Do[k = n; While[ Apply[ Plus, IntegerDigits[k, base] ]*n != k && k < 250n, k += n]; If[k == 250n, Print[n] ], {n, 1, 10^3} ]
  • Python
    from itertools import count, islice, combinations_with_replacement
    from sympy.ntheory import digits
    def A058906_gen(startvalue=1): # generator of terms >= startvalue
        for n in count(max(startvalue,1)):
            for l in count(1):
                if 10*l*n < 11**(l-1):
                    yield n
                    break
                for d in combinations_with_replacement(range(11),l):
                    if (s:=sum(d)) > 0 and sorted(digits(s*n,11)[1:]) == list(d):
                        break
                else:
                    continue
                break
    A058906_list = list(islice(A058906_gen(),20)) # Chai Wah Wu, May 09 2023