A352381 - OEIS

%I #13 Mar 16 2022 03:18:28

%S 14,17,19,77,89,94,95,97,127,134,139,147,149,164,167,169,177,184,190,

%T 194,195,197,199,209,215,217,227,239,244,245,247,764,767,769,827,839,

%U 844,845,847,877,884,889,899,914,917,919,925,934,940,944,947,949,959,965,967,977,989,995,997,1259,1264,1267

%N Numbers k such that no nonzero digit of 4*k divides 4*k.

%e a(1) = 14 and 4*14 = 56 is not divisible by 5 or 6;

%e a(2) = 17 and 4*17 = 68 is not divisible by 6 or 8;

%e a(3) = 19 and 4*19 = 76 is not divisible by 7 or 6;

%e a(4) = 77 and 4*77 = 308 is not divisible by 3, 0 or 8; etc.

%e 26 is not in the sequence as 4*26 = 104 is divisible by 1 (and 4).

%t q[n_] := AllTrue[IntegerDigits[4*n], # == 0 || !Divisible[4*n, #] &]; Select[Range[1270], q] (* _Amiram Eldar_, Mar 14 2022 *)

%o (Python)

%o def ok(n): return not any(4*n%int(d)==0 for d in set(str(4*n)) if d!='0')

%o print([k for k in range(1, 978) if ok(k)]) # _Michael S. Branicky_, Mar 14 2022

%Y Cf. A038772, A352379, A352380, A352382.

%K base,nonn

%O 1,1

%A _Eric Angelini_ and _Carole Dubois_, Mar 14 2022