

A139212


Number of vowels in the preceding terms spelled out in French.


6



0, 2, 4, 7, 8, 10, 11, 13, 16, 19, 22, 25, 27, 29, 32, 36, 39, 43, 49, 55, 60, 64, 71, 78, 85, 90, 95, 102, 105, 107, 109, 112, 116, 120, 122, 126, 129, 133, 138, 143, 150, 155, 161, 168, 175, 183, 190, 196, 204, 210, 214, 221, 227, 232, 239, 246, 254, 264, 274, 285, 293, 303, 308, 313, 319, 325, 330, 335, 341, 350, 357, 365, 373, 383
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OFFSET

1,2


COMMENTS

Form a sequence of French words as follows: look to the left, towards the beginning of the sequence and write down the number of vowels you see; repeat; then replace the words by the corresponding numbers.
The sequence of words is: zero, deux, quatre, sept, huit, dix, onze, treize, seize, ...
Hyphens, accents and spaces are not counted.


REFERENCES

E. Angelini, "Jeux de suites", in Dossier Pour La Science, pp. 3235, Volume 59 (Jeux math'), April/June 2008, Paris.


LINKS



EXAMPLE

The second word is "deux" (and so a(2)=2 for the 'e' and the 'u'), because at the end of the first word ("zéro") we can see two vowels ('e' and 'o') to the left.


PROG

(PARI) a(n)={ n>1  return; #select(Vec(French(n=a(n1))), x>setsearch(Vec("aeiou"), x))+n } /* see A167507 for French() */
/* Version with memoization for better performance when n >> 100: */
A139212(n)={ type(a139212)!="t_VEC" && a139212=[];
n > #a139212 && a139212=concat( a139212, vector(n#a139212));
(a139212[n]  n==1) && return(a139212[n]);
a139212[n]=/*up to here only memoization, could be omitted*/


CROSSREFS

For an English version see A139282.


KEYWORD

nonn,word,easy


AUTHOR



EXTENSIONS

Fixed offset (according to example) and typo in example. M. F. Hasler, Sep 29 2011


STATUS

approved



