A082797 - OEIS

%I #18 Dec 05 2013 19:56:13

%S 7,70,72,72,70,72,7,72,72,70,77,72,78,70,75,704,714,72,76,700,714,704,

%T 713,72,75,78,702,700,725,720,713,704,726,714,70,72,74,76,78,720,738,

%U 714,731,704,720,736,705,720,735,700,714,728,742,702,715

%N Smallest multiple of n beginning with 7.

%C a(n) is in {n, 2n, 3n, 4n, 5n, 6n, 7n, 8n, 9n, 11n, 12n, 13n, 14n, 15n, 16n, 17n, 18n, 21n, 22n, 23n, 24n, 25n, 26n, 27n, 31n, 32n, 33n, 34n, 35n, 41n, 42n, 43n, 44n, 51n, 52n, 53n, 61n, 62n}. [_Charles R Greathouse IV_, Mar 06 2011]

%H Reinhard Zumkeller, <a href="/A082797/b082797.txt">Table of n, a(n) for n = 1..10000</a>

%t f[n_] := Block[{m = n}, While[ First@ IntegerDigits@ m != 7, m += n]; m]; Array[f, 55] (* _Robert G. Wilson v_ *)

%o (PARI) a(n)=forstep(k=n, 62*n, n, if(Vec(Str(k))[1]=="7", return(k))) \\ _Charles R Greathouse IV_, Mar 06 2011

%o (Haskell)

%o a082797 n = until ((== 7) . a000030) (+ n) n

%o -- _Reinhard Zumkeller_, Mar 27 2012

%Y Cf. A082794, A082795, A082796, A082798.

%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