A119293 - OEIS

%I #27 May 02 2019 15:12:02

%S 3,26,339,4070,55213,632418,7133747,82051293,1041785731,12182327373,

%T 137771632675,1525041000685

%N Total number of 2's digits in the first 10^n primes.

%C Count the 2's digits in 10^n primes.

%e At a(1)=3 there are 3 2's digits in the first 10^1 primes.

%p 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

%t Table[Count[IntegerDigits[Prime[Range[10^n]]], 2, 2], {n, 6}] (* _Robert Price_, May 02 2019 *)

%Y Cf. A119290, A119291-A119292, A119294-A119300.

%K more,nonn,base

%O 1,1

%A _Enoch Haga_, May 13 2006

%E Offset changed from 0 to 1 by _Nathaniel Johnston_, May 09 2011

%E a(8)-a(11) from _Robert Price_, Nov 05 2013

%E a(12) from _Marek Hubal_, Mar 04 2019