OFFSET
1,1
COMMENTS
These numbers are haiku when written in English (including the 'and' between the hundreds and tens or units). A haiku is a three-line poem with 5 syllables in the first line, seven in the second and five in the third.
Apparently the actual criterion is that there are 17 syllables, as words can be broken across lines: e.g.,
One hundred and sev-
en thousand one hundred and
seventy-seven. - Robert Israel, Nov 11 2018
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
77777 is a haiku:
Seventy-seven
thousand, seven hundred and
seventy-seven.
MAPLE
filter:= proc(n) uses StringTools; local t;
t:= convert(n, english, 'And');
t:= subs("ninety"="eighty", Split(t, "- "));
# Maple thinks "ninety" has 3 syllables
convert(map(SyllableLength, t), `+`)=17
end proc:
select(filter, [$1..110000]); # Robert Israel, Nov 11 2018
CROSSREFS
KEYWORD
nonn,word,base,fini
AUTHOR
Matthew Scroggs, Nov 01 2018
STATUS
approved