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Total number of 9's digits in the first 10^n primes.
20

%I #30 Mar 04 2019 10:38:36

%S 2,33,431,6318,72062,806674,9004550,104220797,1131743629,12266783460,

%T 131900123107,1447662128808

%N Total number of 9's digits in the first 10^n primes.

%e At a(3)=431 there are 431 9's digits in the first 10^3 = 1000 primes.

%p A119300 := proc(n) option remember: local k,s,lim: if(n=0)then return 0:fi: lim:=10^n: s:=procname(n-1): for k from 10^(n-1)+1 to lim do s:=s+nops([SearchAll("9",convert(ithprime(k),string))]): od: return s: end: seq(A119300(n),n=1..4); # _Nathaniel Johnston_, May 09 2011

%t cnt=0; k=0; Table[While[k++; cnt=cnt+DigitCount[Prime[k], 10, 9];k < 10^n]; cnt, {n, 5}] (* _T. D. Noe_, May 10 2011 *)

%Y Cf. A119290, A119291-A119299.

%K more,nonn,base

%O 1,1

%A _Enoch Haga_, May 13 2006

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

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