

A174416


Numbers whose binary expansion is a decimal nonprime.


2



1, 2, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70
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OFFSET

1,2


COMMENTS



LINKS



EXAMPLE

For n=6, a(6) = 8; binary expansion of 8 = 1000 (nonprime).


MAPLE

remove(t > isprime(convert(t, binary)), [$1..100]); # Robert Israel, Jun 13 2017


MATHEMATICA

Select[Range[80], !PrimeQ[FromDigits[IntegerDigits[#, 2]]]&] (* Harvey P. Dale, May 10 2012 *)


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS

Corrected and extended by Harvey P. Dale, May 10 2012


STATUS

approved



