A082792 - OEIS

%I #22 Mar 30 2021 15:20:51

%S 3,30,3,32,30,30,35,32,36,30,33,36,39,308,30,32,34,36,38,300,315,308,

%T 322,312,300,312,324,308,319,30,31,32,33,34,35,36,37,38,39,320,328,

%U 336,301,308,315,322,329,336,343,300,306,312,318,324,330,336,342,348,354

%N Smallest multiple of n beginning with 3.

%C a(n) is in {n, 2n, 3n, 4n, 5n, 6n, 7n, 8n, 11n, 12n, 13n, 14n, 15n, 21n, 22n, 23n}. - _Charles R Greathouse IV_, Mar 06 2011

%H Reinhard Zumkeller, <a href="/A082792/b082792.txt">Table of n, a(n) for n = 1..10000</a>

%t f[n_] := Block[{m = n}, While[ First@ IntegerDigits@ m != 3, m += n]; m]; Array[f, 59] (* _Robert G. Wilson v_, Mar 06 2011 *)

%o (PARI) a(n)=forstep(k=n,23*n,n,if(Vec(Str(k))[1]=="3",return(k))) \\ _Charles R Greathouse IV_, Mar 06 2011

%o (Haskell)

%o a082792 n = until ((== 3) . a000030) (+ n) n

%o -- _Reinhard Zumkeller_, Mar 27 2012

%o (Python)

%o def a(n):

%o   kn = n

%o   while str(kn)[0] != '3': kn += n

%o   return kn

%o print([a(n) for n in range(1, 60)]) # _Michael S. Branicky_, Mar 30 2021

%Y Cf. A082793, A082794, A082795, A082796.

%Y Cf. A000030.

%K base,easy,nonn

%O 1,1

%A _Amarnath Murthy_, Apr 20 2003

%E Corrected and extended by _Sean A. Irvine_, Mar 06 2011