

A230956


Semiprimes k with a semiprime number of syllables in their name in American English.


3



57, 74, 87, 106, 111, 121, 122, 123, 129, 133, 134, 141, 142, 143, 145, 146, 155, 158, 159, 161, 166, 169, 183, 185, 194, 201, 202, 203, 205, 206, 209, 217, 221, 226, 235, 249, 253, 254, 259, 262, 265, 289, 291, 295, 298, 299, 301, 302, 303, 305, 309
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OFFSET

1,1


COMMENTS

This is to A163648 as semiprimes A001358 are to primes A000040.
The word "and" is excluded, 101 is "one hundred one" rather than "one hundred and one."
Number of syllables in n in American English is A075774.
See A231073 and A231075 for prime analogs counting words respectively letters.


LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000


FORMULA

{k: k is in A001358 and A075774(k) is in A001358}.


EXAMPLE

87 is in the sequence because 87 = 3 * 29 is semiprime, "eightyseven" has 4 syllables, and 4 = 2^2 is also semiprime.
106 is in the sequence because 106 = 2 * 53 is semiprime and "one hundred six" has semiprime 4 syllables.
111 is in the sequence because 111 = 3 * 37 is semiprime and "one hundred eleven" has semiprime 6 = 2*3 syllables.


CROSSREFS

Cf. A001358, A075774, A163648, A231073, A231075.
Sequence in context: A067809 A176636 A072054 * A039429 A043252 A044032
Adjacent sequences: A230953 A230954 A230955 * A230957 A230958 A230959


KEYWORD

nonn,word,easy


AUTHOR

Jonathan Vos Post, Nov 04 2013


EXTENSIONS

Corrected and extended by Charles R Greathouse IV, Jan 23 2014


STATUS

approved



