

A059852


Consider the English alphabet in the International Morse radio telegraph code. Map a 'dit' to the digit one and a 'dah' to the digit 2, then express that ternary number in decimal.


9



5, 67, 70, 22, 1, 43, 25, 40, 4, 53, 23, 49, 8, 7, 26, 52, 77, 16, 13, 2, 14, 41, 17, 68, 71, 76
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OFFSET

1,1


COMMENTS

Written in base 3, the terms read (12, 2111, 2121, 211, 1, 1121, 221, 1111, 11, 1222, 212, 1211, 22, 21, 222, 1221, 2212, 121, 111, 2, 112, 1112, 122, 2112, 2122, 2211). This contains all words over {1,2} with 1 to 4 letters except for 1122, 1212, 2221 and 2222, which correspond to the codes for Ü, Ä, Ö and CH.  M. F. Hasler, Jun 22 2020


REFERENCES

"Learning the Radiotelegraph Code," Seventh Edition, published by American Radio Relay League, West Hartford 7, Connecticut, 1955.
"Morse Code Course," Jeppesen and Company, Denver, Colorado, 1962.
"International Morse Code," prepared by Lt. Commander F.R.L. Tuthill, USNR and Lt. (J.G.) E.L. Battey, USNR, published by Insuline Corporation of America, Long Island City, NY.


LINKS

Table of n, a(n) for n=1..26.
Wikipedia, Morse code.


EXAMPLE

The sixth letter, F, is ".._." in Morse. This becomes 1121 in ternary and 43 in decimal, so a(6) = 43.


PROG

(PARI) A059852=digits(3008707498660932665486381130661318784490079420090, 81) \\ or vecextract(apply(A032924, [1..28]), i) with i=numtoperm(26, 58849338891424664724588744) or i=vecsort(Vec("ETIANMSURWDKGOHVFuLaPJBXCYZQ"), , 1)[1..26].  M. F. Hasler, Jun 22 2020


CROSSREFS

Cf. A060110, the same for numbers, and A060109, written in base 3.
Cf. A008777 (number of base 3 digits = dots and dashes in the nth letter), A281015, A281017, A281018.
Cf. A105386, A105387 (ambiguous variants using digits 0 and 1).
Sequence in context: A156597 A059489 A197161 * A057171 A185230 A142009
Adjacent sequences: A059849 A059850 A059851 * A059853 A059854 A059855


KEYWORD

base,easy,fini,full,nonn,word


AUTHOR

Robert G. Wilson v, Feb 27 2001


EXTENSIONS

Edited, links and crossrefs added by M. F. Hasler, Jun 22 2020


STATUS

approved



