

A227290


Repeatedly map numbers to number of letters in English name (A005589); sequence gives first number that needs n steps to get to 4.


1




OFFSET

0,1


COMMENTS

Based on the observation by Diane Karloff that the trajectory of A005589 always converges to 4.
40311123323 (concatenation of the first seven terms) is the first time prime is obtained when concatenating k first initial terms of the sequence.  Jonathan Vos Post, Jul 06 2013, edited by Antti Karttunen, Jul 25 2013


LINKS



EXAMPLE

"eleven" has 6 letters, "six" has 3 letters, "three" has 5 letters, "five" has 4 letters.
So a(4)=11, as A005589^4(11)=4 and 11 is the first such number.
But a(3)=1, because "one" is the same length as "six".


CROSSREFS



KEYWORD

nonn,word


AUTHOR



STATUS

approved



