cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A097952 Sum of the number of digits in the prime numbers less than 10^n.

Original entry on oeis.org

0, 4, 46, 475, 4719, 46534, 459970, 4562537, 45337545, 451112256, 4493162026, 44786187348, 446664473808, 4456613596481, 44480880591963, 444075310669968, 4434375640450064, 44287795522995300, 442382943864554586
Offset: 0

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Author

Cino Hilliard, Sep 05 2004

Keywords

Comments

Partial sums of A046719(n) = n*A006879(n). In other words, a(n) is the number of digits used in writing out all {A006880(n)} primes below 10^n. - Lekraj Beedassy, Dec 13 2007

Examples

			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.
		

Crossrefs

Programs

  • 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 *)
  • PARI
    g(n) = for(j=0,n,s=0;forprime(x=2,10^j,y=length(Str(x));s+=y);print1(s","))

Formula

a(n) = Sum_{k=0..n} k * A006879(k). - Amiram Eldar, Jul 04 2024

Extensions

More terms derived from A006879 by R. J. Mathar, Oct 14 2010