A281018 - OEIS

A281018

Numbers with a prime number of dots and a prime number of dashes in their International Morse numeral representation.

2, 3, 7, 8, 12, 14, 16, 18, 21, 23, 25, 27, 29, 30, 32, 34, 36, 38, 41, 43, 47, 49, 50, 52, 58, 61, 63, 67, 69, 70, 72, 74, 76, 78, 81, 83, 85, 87, 89, 92, 94, 96, 98, 101, 109, 110, 190, 200, 355, 445, 454, 456, 465, 535, 544, 546, 553, 557, 564, 566, 575, 645

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

This uses the current ITU standard Morse code.

This sequence is the intersection of A281015 and A281017.

LINKS

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

Wikipedia, Morse Code

EXAMPLE

27 is in the sequence because it is both in A281015 and A281017.

PROG