OFFSET
1,1
COMMENTS
Count the 2's digits in 10^n primes.
EXAMPLE
At a(1)=3 there are 3 2's digits in the first 10^1 primes.
MAPLE
A119293 := proc(n) option remember: local k, s, lim: if(n=0)then return 1:fi: lim:=10^n: s:=procname(n-1): for k from 10^(n-1)+1 to lim do s:=s+nops([SearchAll("2", convert(ithprime(k), string))]): od: return s: end: seq(A119293(n), n=1..4); # Nathaniel Johnston, May 09 2011
MATHEMATICA
Table[Count[IntegerDigits[Prime[Range[10^n]]], 2, 2], {n, 6}] (* Robert Price, May 02 2019 *)
CROSSREFS
KEYWORD
more,nonn,base
AUTHOR
Enoch Haga, May 13 2006
EXTENSIONS
Offset changed from 0 to 1 by Nathaniel Johnston, May 09 2011
a(8)-a(11) from Robert Price, Nov 05 2013
a(12) from Marek Hubal, Mar 04 2019
STATUS
approved