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Prime numbers whose (British) English names have a prime number of letters.
4

%I #6 Nov 05 2013 06:27:47

%S 2,3,7,23,37,79,83,97,109,139,157,163,167,199,211,229,239,257,263,271,

%T 313,401,421,431,449,491,503,521,569,643,647,653,709,719,751,761,809,

%U 907,991,1021,1031,1049,1069,1091,1103,1301,1303,1307,1327,1409,1511

%N Prime numbers whose (British) English names have a prime number of letters.

%C See A231075 for the American English version. The sequences coincide up to a(8)=97 but are then completely different, due to the additional "and" (e.g. in "one hundred and nine") in the British style. - _M. F. Hasler_, Nov 03 2013

%H <a href="/index/Lc#letters">Index entries for sequences related to number of letters in n</a>

%e e.g. 2003 -> "TWOTHOUSANDANDTHREE" -> 19 letters and 19 is prime. Note that the "and" naming convention is used; e.g. "ONE HUNDRED AND ONE", "ONE THOUSAND NINE HUNDRED AND SEVENTY THREE".

%Y Prime elements of A072685.

%K easy,nonn,word

%O 0,1

%A Mark Hudson (mrmarkhudson(AT)hotmail.com), Jul 02 2002