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A139097 Form a sequence of words as follows: look to the left, towards the beginning of the sequence and write down the number of letters you see; repeat; then replace the words with the corresponding numbers. 4
0, 4, 8, 13, 21, 30, 36, 45, 54, 63, 73, 85, 95, 105, 119, 137, 158, 178, 200, 211, 227, 248, 268, 288, 309, 325, 347, 369, 390, 408, 424, 445, 465, 485, 506, 520, 537, 559, 579, 601, 614, 632, 651, 669, 688, 709, 725, 747, 769, 790, 808, 825, 847, 869, 890, 908, 924, 945, 965, 985, 1006, 1020, 1037, 1059 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
The sequence of words is: zero, four, eight, thirteen, twenty-one, thirty, ... (in American English).
Hyphens and spaces are not counted.
This is an English version of the sequence in A139121.
a(0) = 0, a(n+1) = a(n) + A005589(a(n)). - Jonathan Vos Post, Jun 15 2008
REFERENCES
E. Angelini, "Jeux de suites", in Dossier Pour La Science, pp. 32-35, Volume 59 (Jeux math'), April/June 2008, Paris.
LINKS
EXAMPLE
The second word is "four" (and so a(2)=4), because at the end of the first word we can see four letters to the left.
CROSSREFS
Cf. A005589. See A060403 and A139121 for other versions.
Sequence in context: A312220 A335445 A060403 * A160395 A038793 A036709
KEYWORD
nonn,word,easy
AUTHOR
Jonathan Vos Post, May 12 2007
EXTENSIONS
Edited by N. J. A. Sloane, Jun 08 2008
More terms from M. F. Hasler and R. J. Mathar, Jun 15 2008
STATUS
approved

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Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)