A244356 Numbers n such that n and n+1 are not divisible by any of their nonzero digits.

37, 46, 53, 56, 57, 58, 67, 68, 73, 78, 86, 97, 307, 337, 346, 358, 373, 376, 379, 388, 397, 406, 429, 433, 446, 457, 466, 469, 473, 477, 478, 489, 493, 498, 506, 507, 508, 538, 553, 556, 557, 558, 577, 578, 586, 587, 588, 596, 597, 598, 646, 656, 657, 658, 667, 668, 669

Offset: 1

Author

Derek Orr, Jun 26 2014

Keywords

• nonn
• base
• look

Comments

This is a subsequence of A038772.

All numbers end in a 3, 6, 7, 8, or 9.

Examples

			37 is not divisible by 3 or 7 and 38 is not divisible by 3 or 8. Thus 37 is a member of this sequence.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A038772, A237766.

Programs

Maple

filter:= proc(n) local L;
  L:= convert(convert(n,base,10), set) minus {0};
  not ormap(t -> n mod t = 0, L)
end proc:
B:= select(filter, {$1..1000}):
sort(convert(B intersect map(`-`,B,1), list)); # Robert Israel, Dec 08 2019

Python

def a(n):
  for i in range(10**3):
    tot = 0
    for k in range(i,i+n):
      c = 0
      for b in str(k):
        if b != '0':
          if k%int(b)!=0:
            c += 1
      if c == len(str(k))-str(k).count('0'):
        tot += 1
    if tot == n:
      print(i,end=', ')
a(2)