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.

A352381 Numbers k such that no nonzero digit of 4*k divides 4*k.

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%I A352381 #13 Mar 16 2022 03:18:28
%S A352381 14,17,19,77,89,94,95,97,127,134,139,147,149,164,167,169,177,184,190,
%T A352381 194,195,197,199,209,215,217,227,239,244,245,247,764,767,769,827,839,
%U A352381 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 A352381 Numbers k such that no nonzero digit of 4*k divides 4*k.
%e A352381 a(1) = 14 and 4*14 = 56 is not divisible by 5 or 6;
%e A352381 a(2) = 17 and 4*17 = 68 is not divisible by 6 or 8;
%e A352381 a(3) = 19 and 4*19 = 76 is not divisible by 7 or 6;
%e A352381 a(4) = 77 and 4*77 = 308 is not divisible by 3, 0 or 8; etc.
%e A352381 26 is not in the sequence as 4*26 = 104 is divisible by 1 (and 4).
%t A352381 q[n_] := AllTrue[IntegerDigits[4*n], # == 0 || !Divisible[4*n, #] &]; Select[Range[1270], q] (* _Amiram Eldar_, Mar 14 2022 *)
%o A352381 (Python)
%o A352381 def ok(n): return not any(4*n%int(d)==0 for d in set(str(4*n)) if d!='0')
%o A352381 print([k for k in range(1, 978) if ok(k)]) # _Michael S. Branicky_, Mar 14 2022
%Y A352381 Cf. A038772, A352379, A352380, A352382.
%K A352381 base,nonn
%O A352381 1,1
%A A352381 _Eric Angelini_ and _Carole Dubois_, Mar 14 2022