|
|
A097952
|
|
Sum of the number of digits in the prime numbers less than 10^n.
|
|
12
|
|
|
0, 4, 46, 475, 4719, 46534, 459970, 4562537, 45337545, 451112256, 4493162026, 44786187348, 446664473808, 4456613596481, 44480880591963, 444075310669968, 4434375640450064, 44287795522995300, 442382943864554586
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
There are 25 primes < 100; 4 of them are 1-digit numbers and 21 are 2-digit numbers. Thus a(2) = 4 + 21*2 = 46.
|
|
MATHEMATICA
|
Accumulate[Table[n(PrimePi[10^n]-PrimePi[10^(n-1)]), {n, 0, 14}]] (* This generates the first 15 terms of the sequence, but if n exceeds 14 the function PrimePi in Mathematica cannot calculate it. *) (* Harvey P. Dale, Jun 13 2014 *)
|
|
PROG
|
(PARI) g(n) = for(j=0, n, s=0; forprime(x=2, 10^j, y=length(Str(x)); s+=y); print1(s", "))
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|