A058903 Inconsummate numbers in base 7: no number is this multiple of the sum of its digits (in base 7).

30, 86, 102, 134, 138, 141, 158, 162, 167, 170, 183, 186, 194, 210, 213, 233, 284, 290, 306, 312, 314, 326, 330, 338, 354, 362, 366, 368, 428, 452, 480, 530, 534, 536, 540, 542, 554, 564, 578, 591, 602, 645, 648, 656, 705, 708, 714, 740, 746

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..10214

Maple

For Maple code see A058906.

Mathematica

base=7; Do[k=n; While[Apply[Plus, IntegerDigits[k, base]] n!=k&&k<250n, k+=n]; If[k==250 n, Print[n]], {n, 1, 10^3}] (* Vincenzo Librandi, Jan 30 2017 *)

Prog

(Python)
from itertools import count, islice, combinations_with_replacement
from sympy.ntheory import digits
def A058903_gen(startvalue=1): # generator of terms >= startvalue
    for n in count(max(startvalue, 1)):
        for l in count(1):
            if 6*l*n < 7**(l-1):
                yield n
                break
            for d in combinations_with_replacement(range(7), l):
                if (s:=sum(d)) > 0 and sorted(digits(s*n, 7)[1:]) == list(d):
                    break
            else:
                continue
            break
A058903_list = list(islice(A058903_gen(), 20)) # Chai Wah Wu, May 10 2023

Crossrefs

Cf. A003635, A052491, A058898-A058907.

Sequence in context: A098996 A130862 A070756 * A254474 A103906 A124799

Adjacent sequences: A058900 A058901 A058902 * A058904 A058905 A058906

Keyword

nonn,base

Author

N. J. A. Sloane, Jan 09 2001

Status

approved