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A020452 Primes that contain digits 1 and 4 only. 9
11, 41, 4111, 4441, 11411, 14411, 41141, 41411, 44111, 1114111, 1144141, 1144441, 1411141, 1411411, 1441411, 1444111, 1444411, 1444441, 4141441, 4414411, 4441111, 4441441, 11111141, 11141111, 11141441, 11441141, 11441411, 14111441, 14141411 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

MATHEMATICA

Flatten[Table[Select[FromDigits/@Tuples[{1, 4}, n], PrimeQ], {n, 8}]] (* Vincenzo Librandi, Jul 27 2012 *)

PROG

(MAGMA) [p: p in PrimesUpTo(14141411) | Set(Intseq(p)) subset [1, 4]]; // Bruno Berselli, Jul 27 2012

(Python)

import sympy

def checkd(a, c):

....b=[int(i) for i in list(set(list(str(a))))]

....return(set(b).issubset(c))

n=2

while n>1:

....if checkd(n, [1, 4])==True:

........print(n)

....n=sympy.nextprime(n)

// Abhiram R Devesh, May 08 2015

CROSSREFS

Sequence in context: A257967 A104118 A159561 * A249413 A003356 A063152

Adjacent sequences:  A020449 A020450 A020451 * A020453 A020454 A020455

KEYWORD

nonn,base

AUTHOR

David W. Wilson

STATUS

approved

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Last modified October 15 03:09 EDT 2019. Contains 328025 sequences. (Running on oeis4.)