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A227857
Number of numbers whose American English name has no letter in common with that of n.
4
5, 7, 29, 15, 36, 3, 95, 11, 1, 5, 2, 19, 2, 0, 1, 0, 1, 1, 1, 1, 2, 1, 1, 1, 1, 0, 1, 1, 1, 1, 3, 0, 2, 0, 2, 0, 2, 0, 0, 0, 4, 1, 4, 1, 4, 0, 1, 0, 0, 0, 12, 0, 5, 0, 2, 0, 6, 0, 0, 0, 12, 0, 1, 0, 1, 0, 12, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1
OFFSET
0,1
COMMENTS
The sequence is well defined and zero for n sufficiently large (> 6.1*10^30 ?) because "million", "billion" etc. have a letter in common with all small numbers except for three, which is letter-disjoint with six. Therefore, 3 is letter-disjoint with six, six million, six billion, six nonillion (10^30) and any nonempty sum of two or more of these. See also example of a(5).
EXAMPLE
a(0) = 5 = # {6, 50, 56, 60, 66} because "zero" has no letter in common with: six, fifty, fifty-six, sixty, sixty-six.
a(5) = 3 = # {2, 2000, 2002} because "five" has no letter in common with: two, two thousand, two thousand two. ("thousand" is not considered; "one thousand" is excluded.)
a(3) = 15 = 2^4-1 because any nonzero sum_{i=0,6,9,30} e_i*10^i with e_i in {0, 6} is "letter-disjoint" with three.
PROG
(PARI) A227857(n, lang=English/*see A052360*/, L=999, o=0)={n==5 && L+=2000; n==3 && return(15)/*can't be computed explicitely*/; n=setminus(Set(Vec(lang(n))), Set([" ", "-"])); sum(k=o, L, !setintersect( Set(Vec(lang(k))), n))}
CROSSREFS
Sequence in context: A179305 A307100 A229337 * A266078 A147993 A213901
KEYWORD
nonn,word
AUTHOR
M. F. Hasler, Nov 04 2013
STATUS
approved