A187285 - OEIS

%I #11 Jul 13 2013 12:03:48

%S 1,10,12,12,10,12,14,16,18,10,11,12,13,14,15,16,17,18,19,100,105,110,

%T 115,120,100,104,108,112,116,120,124,128,132,102,105,108,111,114,117,

%U 120,123,126,129,132,135,138,141,144,147,100,102,104,106,108,110

%N Smallest multiple of n beginning with 1.

%C a(n) is in {n, 2n, 3n, 4n, 5n}. [_Charles R Greathouse IV_, Mar 07 2011]

%H Reinhard Zumkeller, <a href="/A187285/b187285.txt">Table of n, a(n) for n = 1..10000</a>

%t f[n_] := Block[{m = n}, While[ First@ IntegerDigits@ m != 1, m += n]; m]; Array[f, 55]

%o (PARI) a(n)=forstep(k=n, 5*n, n, if(Vec(Str(k))[1]=="1", return(k))) \\ _Charles R Greathouse IV_, Mar 07 2011

%o (Haskell)

%o a187285 n = until ((== 1) . a000030) (+ n) n

%o -- _Reinhard Zumkeller_, Mar 27 2012

%Y Cf. A082811, A082792, A082794, A082795, A082796, A082797, A082798, A187090.

%Y Cf. A000030.

%K base,nonn

%O 1,2

%A _Robert G. Wilson v_, Mar 07 2011