A055728 Number of prime lucky numbers <10^n.
0, 2, 9, 43, 211, 1300, 8616, 62446, 469146, 3656784, 29285501, 239911086
Offset: 0
Examples
a(2) = 9 since there are 9 prime numbers in the lucky number sequence A000959 that are less than 10^2 (3, 7, 13, 31, 37, 43, 67, 73, and 79).
Programs
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Mathematica
lst = Range[1, 10^8, 2]; i = 2; While[ i <= (len = Length@lst) && (k = lst[[i]]) <= len, lst = Drop[lst, {k, len, k}]; i++ ]; Table[Length@ Select[lst, PrimeQ@# && # < 10^n &], {n, 0, 8}] (* Robert G. Wilson v, May 12 2006 *)
Extensions
a(7)-a(8) from Robert G. Wilson v, May 12 2006
a(9) from Donovan Johnson, Jul 06 2010
a(10) from Kevin P. Thompson, Nov 22 2021
a(11) from Dana Jacobsen, Mar 08 2023