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A096683 Least k such that decimal representation of k*n contains only digits 0 and 4. 2
4, 2, 148, 1, 8, 74, 572, 5, 49382716, 4, 4, 37, 308, 286, 296, 25, 2612, 24691358, 2316, 2, 1924, 2, 19148, 185, 16, 154, 163127572, 143, 151876, 148, 14324, 125, 13468, 1306, 1144, 12345679, 12, 1158, 1036, 1, 1084, 962, 102428, 1, 98765432 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert G. Wilson v, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A078243(n)/n.

MATHEMATICA

f[n_] := Block[{id = {0, 4}, k = 1}, While[ Union[ Join[id, IntegerDigits[k*n]]] != id, k++]; k]; Array[f, 100] (* or *)

id = {0, 7}; lst = Union[ FromDigits /@ Flatten[ Table[ Tuples[id, j], {j, 15}], 1]]; If[ lst[[1]] == 0, lst = Rest@ lst]; f[n_] := (Min[ Select[lst, Mod[#, n] == 0 &]]/n) /. Infinity -> 0; Array[f, 100] (* or *)

id = {0, 7}; lst = Union[ FromDigits /@ Flatten[ Table[ Tuples[id, j], {j, 15}], 1]]; If[ lst[[1]] == 0, lst = Rest@ lst]; f[n_] := (SelectFirst[lst, Mod[#, n] == 0 &, 0]/n); a = Array[f, 100] (* requires Mathematica v10 *) (* Robert G. Wilson v, Sep 26 2016 *)

CROSSREFS

Cf. A004290, A078241-A078248, A079339, A096681, A096682, A096684, A096685, A096686, A096687, A096688.

Sequence in context: A010319 A266069 A057167 * A158903 A273148 A276342

Adjacent sequences:  A096680 A096681 A096682 * A096684 A096685 A096686

KEYWORD

base,nonn

AUTHOR

Ray Chandler, Jul 12 2004

STATUS

approved

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Last modified November 22 06:06 EST 2018. Contains 317453 sequences. (Running on oeis4.)