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A281017 Numbers with a prime number of dashes in their International Morse numeral representation. 3
0, 2, 3, 7, 8, 12, 14, 16, 18, 21, 23, 25, 27, 29, 30, 32, 34, 35, 36, 38, 41, 43, 44, 46, 47, 49, 50, 52, 53, 57, 58, 61, 63, 64, 66, 67, 69, 70, 72, 74, 75, 76, 78, 81, 83, 85, 87, 89, 92, 94, 96, 98, 101, 103, 107, 109, 110, 112, 118, 121, 125, 129, 130, 134 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The Morse code is written in current ITU standard.

LINKS

Indranil Ghosh, Table of n, a(n) for n = 1..10000

Wikipedia, Morse Code

EXAMPLE

27 is in the sequence because 27 in its Morse numeral representation is written as '..--- --...' which has 5 dashes and 5 is prime.

PROG

(Python)

from sympy import isprime

i=0

j=1

while j<=10000:

    if isprime(A280916(i))==True :

        print str(j)+" "+str(i)

        j+=1

    i+=1

CROSSREFS

Cf. A280916, A280998, A280999, A281015.

Sequence in context: A047221 A032967 A111101 * A281018 A184860 A242655

Adjacent sequences:  A281014 A281015 A281016 * A281018 A281019 A281020

KEYWORD

nonn,base

AUTHOR

Indranil Ghosh, Jan 13 2017

STATUS

approved

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Last modified October 20 17:41 EDT 2019. Contains 328268 sequences. (Running on oeis4.)