A334963 - OEIS

A334963

a(n) is the least positive multiple of n that has at most two distinct digits.

%I #22 Jan 08 2021 10:53:01

%S 1122,515,1144,525,212,535,1188,545,110,111,112,113,114,115,116,117,

%T 118,119,600,121,122,3444,744,500,252,889,4224,774,10010,131,660,133,

%U 4422,4455,272,411,414,556,700,141,994,858,144,3335,292,441,444,447,300,151,2888

%N a(n) is the least positive multiple of n that has at most two distinct digits.

%H David A. Corneth, <a href="/A334963/b334963.txt">Table of n, a(n) for n = 102..10101</a>

%F a(n) <= A004290(n).

%F a(n) = n if n is in A031955. - _Bernard Schott_, May 17 2020

%e a(102) = 1122 as 1122 = 11*102 is the least multiple of 102 that has at most 2 distinct digits.

%t a[n_] := Module[{k = n}, While[Length @ Select[DigitCount[k, 10], # > 0 &] > 2, k += n]; k]; Array[a, 51, 102] (* _Amiram Eldar_, May 21 2020 *)

%o (PARI) a(n) = for(i = 1, oo, if(#Set(digits(i*n))<3, return(i*n)))

%Y Cf. A004290, A031955, A181060.

%K nonn,base,easy

%O 102,1

%A _David A. Corneth_, May 17 2020