

A081102


Numbers k such that the first k digits of log_10(2) after the decimal point are primes.


0




OFFSET

1,2


LINKS

Table of n, a(n) for n=1..6.


EXAMPLE

1 is listed because 3 is prime but 5 is not listed because 30102 is not prime.


MATHEMATICA

Do[ If[ PrimeQ[ FromDigits[ RealDigits[ N[ Log[10, 2], n + 10], 10, n] [ [1] ] ] ], Print[n] ], {n, 1, 10000} ]


CROSSREFS

Cf. A007524.
Sequence in context: A191494 A269000 A189276 * A250171 A128987 A240788
Adjacent sequences: A081099 A081100 A081101 * A081103 A081104 A081105


KEYWORD

nonn,base,more


AUTHOR

John Sillcox (JMS21187(AT)aol.com), Apr 15 2003


EXTENSIONS

Offset corrected and a(5)a(6) added by Amiram Eldar, Jan 27 2021


STATUS

approved



