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A082794 Smallest multiple of n beginning with 4.

%I A082794 #25 Apr 04 2021 10:12:06
%S A082794 4,4,42,4,40,42,42,40,45,40,44,48,403,42,45,48,408,414,418,40,42,44,
%T A082794 46,48,400,416,405,420,406,420,403,416,429,408,420,432,407,418,429,40,
%U A082794 41,42,43,44,45,46,47,48,49,400,408,416,424,432,440,448,456,406,413
%N A082794 Smallest multiple of n beginning with 4.
%C A082794 a(n) is in {n, 2n, 3n, 4n, 5n, 6n, 7n, 8n, 11n, 12n, 13n, 14n, 15n, 16n, 21n, 22n, 23n, 24n, 31n, 32n}. - _Charles R Greathouse IV_, Mar 06 2011
%H A082794 Vincenzo Librandi, <a href="/A082794/b082794.txt">Table of n, a(n) for n = 1..1000</a>
%p A082794 a:= proc(n) option remember; local m; m:= 0;
%p A082794       do m:=m+n; if (""||m)[1]="4" then break fi od; m
%p A082794     end:
%p A082794 seq(a(n), n=1..60);  # _Alois P. Heinz_, Apr 04 2021
%t A082794 f[n_] := Block[{m = n}, While[ First@ IntegerDigits@ m != 4, m += n]; m]; Array[f, 56] (* _Robert G. Wilson v_ *)
%o A082794 (PARI) a(n)=forstep(k=n, 32*n, n, if(Vec(Str(k))[1]=="4", return(k))) \\ _Charles R Greathouse IV_, Mar 06 2011
%o A082794 (Haskell)
%o A082794 a082794 n = until ((== 4) . a000030) (+ n) n
%o A082794 -- _Reinhard Zumkeller_, Mar 27 2012
%o A082794 (Python)
%o A082794 def a(n):
%o A082794   kn = n
%o A082794   while str(kn)[0] != '4': kn += n
%o A082794   return kn
%o A082794 print([a(n) for n in range(1, 57)]) # _Michael S. Branicky_, Apr 04 2021
%Y A082794 Cf. A082795, A082796, A082797, A082798.
%Y A082794 Cf. A000030.
%K A082794 base,easy,nonn
%O A082794 1,1
%A A082794 _Amarnath Murthy_, Apr 20 2003
%E A082794 More terms from _Sean A. Irvine_, Mar 06 2011