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.

A091644 Number of primes less than 10^n which have at least one digit 0.

Original entry on oeis.org

0, 0, 15, 219, 2470, 26185, 266713, 2658107, 26198216, 256516296, 2501246232, 24320647270, 236032108530, 2287868820615
Offset: 1

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Author

Enoch Haga, Jan 30 2004

Keywords

Comments

3 additional terms, generated using a sieve program. - Ryan Propper, Aug 20 2005

Examples

			a(3) = 15 because of the 168 primes less than 10^3, 15 have at least one 0 digit.
		

Crossrefs

Programs

  • Mathematica
    NextPrim[n_] := Block[{k = n + 1}, While[ ! PrimeQ[k], k++ ]; k]; c = 0; p = 1; Do[ While[ p = NextPrim[p]; p < 10^n, If[ Position[ IntegerDigits[p], 0] != {}, c++ ]]; Print[c]; p--, {n, 1, 8}] (* Robert G. Wilson v, Feb 02 2004 *)
  • Python
    from sympy import sieve # use primerange for larger terms
    def digs0(n): return '0' in str(n)
    def aupton(terms):
      ps, alst = 0, []
      for n in range(1, terms+1):
        ps += sum(digs0(p) for p in sieve.primerange(10**(n-1), 10**n))
        alst.append(ps)
      return alst
    print(aupton(7)) # Michael S. Branicky, Apr 25 2021

Formula

a(n) = A006880(n) - A091634(n).

Extensions

Edited and extended by Robert G. Wilson v, Feb 02 2004
More terms from Ryan Propper, Aug 20 2005
a(13) from Robert Price, Nov 11 2013
a(14) from Giovanni Resta, Jul 21 2015