A119293 Total number of 2's digits in the first 10^n primes.

3, 26, 339, 4070, 55213, 632418, 7133747, 82051293, 1041785731, 12182327373, 137771632675, 1525041000685

Offset: 1

Author

Enoch Haga, May 13 2006

Keywords

• more
• nonn
• base

Comments

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

Examples

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

Crossrefs

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

Programs

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 *)

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