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A113590 Least multiple of prime(n) containing only prime digits (2,3,5,7). 2
2, 3, 5, 7, 22, 52, 255, 57, 23, 232, 372, 37, 533, 2322, 235, 53, 2537, 732, 335, 355, 73, 237, 332, 2225, 2522, 2222, 2575, 535, 327, 2373, 22225, 2227, 7535, 3753, 2235, 755, 2355, 7335, 27555, 23355, 537, 2353, 573, 772, 27777, 5373, 2532, 223, 227, 5725, 233 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(n) = prime(n) if prime(n) is in A019546.

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

MAPLE

N:= 100: # to get a(1)..a(N)

pn:= ithprime(N):

count:= 0:

digs:= [2, 3, 5, 7]:

for d from 1 while count < N do

for m from 4^d to 2*4^d-1 while count < N do

  L:= convert(m, base, 4);

  n:= add(digs[L[i]+1]*10^(i-1), i=1..nops(L)-1);

  ps:= select(p -> p <= pn and not assigned(A[p]), numtheory:-factorset(n));

  count:= count + nops(ps);

  for p in ps do A[p]:= n od:

od od:

seq(A[ithprime(i)], i=1..N); # Robert Israel, Dec 27 2018

CROSSREFS

Cf. A019546, A113591.

Sequence in context: A066483 A114420 A349899 * A124673 A024776 A069867

Adjacent sequences:  A113587 A113588 A113589 * A113591 A113592 A113593

KEYWORD

base,easy,nonn

AUTHOR

Amarnath Murthy, Nov 07 2005

EXTENSIONS

More terms from Nick Woods (njw130(AT)psu.edu), Apr 25 2006

a(44) and a(50) corrected by Robert Israel, Dec 27 2018

STATUS

approved

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Last modified May 27 02:41 EDT 2022. Contains 354093 sequences. (Running on oeis4.)