A072686 Prime numbers whose (British) English names have a prime number of letters.
2, 3, 7, 23, 37, 79, 83, 97, 109, 139, 157, 163, 167, 199, 211, 229, 239, 257, 263, 271, 313, 401, 421, 431, 449, 491, 503, 521, 569, 643, 647, 653, 709, 719, 751, 761, 809, 907, 991, 1021, 1031, 1049, 1069, 1091, 1103, 1301, 1303, 1307, 1327, 1409, 1511
Offset: 0
Examples
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".
Crossrefs
Prime elements of A072685.
Comments