A280916 Number of dashes in International Morse numeral representation of n.

5, 4, 3, 2, 1, 0, 1, 2, 3, 4, 9, 8, 7, 6, 5, 4, 5, 6, 7, 8, 8, 7, 6, 5, 4, 3, 4, 5, 6, 7, 7, 6, 5, 4, 3, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1, 2, 3, 4, 5, 5, 4, 3, 2, 1, 0, 1, 2, 3, 4, 6, 5, 4, 3, 2, 1, 2, 3, 4, 5, 7, 6, 5, 4, 3, 2, 3, 4, 5, 6, 8, 7, 6, 5, 4, 3, 4, 5, 6, 7, 9, 8, 7, 6, 5, 4, 5, 6, 7, 8, 14

Offset

0,1

Comments

The Morse Code is written in current ITU standard.

Links

Indranil Ghosh, Table of n, a(n) for n = 0..10000

Wikipedia, Morse code

Wikipedia, International Telecommunication Union

Formula

a(n) = A316863(A060109(n)) = floor(1+n/10)*5 - A280913(n) = a(floor(n/10)) + a(n%10) if n > 9 or |5 - n| otherwise, where % is the modulo (remainder) operator. - M. F. Hasler, Jun 22 2020

Example

For n = 4, the Morse numeral representation of 4 is "....-" i.e., 1 dash. So, a(4) = 1.
For n = 26, the Morse numeral representation of 26 is "..--- -...." i.e, 4 dashes. So, a(26) = 4.

Mathematica

Array[Total@ Map[Abs[# - 5] &, IntegerDigits[#]] &, 101, 0] (* Michael De Vlieger, Jun 28 2020 *)

Prog

(Python)
M={"1":".----", "2":"..---", "3":"...--", "4":"....-", "5":".....", "6":"-....", "7":"--...", "8":"---..", "9":"----.", "0":"-----"}
def A280916(n):
    z="".join(M[i] for i in str(n))
    return z.count("-")
print([A280916(n) for n in range(100)])
(PARI) apply( {A280916(n)=if(n>9, self()(n\10)+self()(n%10), abs(n-5))}, [0..88]) \\ M. F. Hasler, Jun 22 2020

Crossrefs

Cf. A060109 (Morse code of n), A280913 (number of dots).

Cf. A006968, A278182 (for Roman resp. Maya representation of n).

Sequence in context: A370427 A022961 A023447 * A307336 A031016 A261302

Adjacent sequences: A280913 A280914 A280915 * A280917 A280918 A280919

Keyword

nonn,base

Author

Indranil Ghosh, Jan 10 2017

Status

approved