

A096235


Number of nbit base2 deletable primes.


13



0, 2, 2, 2, 3, 6, 6, 11, 18, 31, 49, 87, 155, 253, 427, 781, 1473, 2703, 5094, 9592, 18376, 35100, 67183, 129119, 249489, 482224, 930633, 1803598, 3502353, 6813094
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OFFSET

1,2


COMMENTS

A prime p is a baseb deletable prime if when written in base b it has the property that removing some digit leaves either the empty string or another deletable prime. However, in base 2 we adopt the convention that 2 = 10 and 3 = 11 are deletable.
Deleting a digit cannot leave any leading zeros in the new string. For example, deleting the 2 in 2003 to obtain 003 is not allowed.


LINKS

Table of n, a(n) for n=1..30.


EXAMPLE

d base2 ddigit deletable primes
2 2=10, 3=11
3 5=101, 7=111
4 11=1011, 13=1101
5 19=10011, 23=10111, 29=11101
6 37=100101, 43=101011, 47=101111, 53=110101, 59=111011, 61=111101
7 73=1001001, 79=1001111, 83=1010011, 101=1100101, 107=1101011, 109=1101101


CROSSREFS

Cf. A080608, A080603, A096236A096246.
Sequence in context: A038715 A293518 A057040 * A147851 A218694 A143596
Adjacent sequences: A096232 A096233 A096234 * A096236 A096237 A096238


KEYWORD

nonn,base,more


AUTHOR

Michael Kleber, Feb 28 2003


EXTENSIONS

12 more terms from Ryan Propper, Jul 18 2005


STATUS

approved



