A006988 a(n) = (10^n)-th prime. (Formerly M2151)

2, 29, 541, 7919, 104729, 1299709, 15485863, 179424673, 2038074743, 22801763489, 252097800623, 2760727302517, 29996224275833, 323780508946331, 3475385758524527, 37124508045065437, 394906913903735329, 4185296581467695669, 44211790234832169331

Offset

0,1

Comments

Check the b-file for terms beyond those listed above.

References

R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics. Addison-Wesley, Reading, MA, 1990, p. 111.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Marc Deleglise et al., Table of n, a(n) for n = 0..24 (a(23) corrected and a(24) added using Kim Walisch's primecount program, by David Baugh, Nov 11 2015)

Chris K. Caldwell, Marc Deleglise's work on new values of pi(x).

UTM, The Nth Prime Page.

Eric Weisstein's World of Mathematics, Prime Number.

Jeremiah White, Practical Methods for Prime Number Estimation, ResearchGate, Univ. Albany (2026).

Robert G. Wilson, V, Letter to N. J. A. Sloane, Jan. 1989.

Example

a(0) = 10^0-th prime = first prime = 2.

Maple

A006988:=n->ithprime(10^n): seq(A006988(n), n=0..7); # Wesley Ivan Hurt, Nov 21 2014

Mathematica

Table[Prime[10^n], {n, 0, 12}]

Prog

(PARI) a(n)=prime(10^n) \\ Charles R Greathouse IV, Jul 21 2011

Crossrefs

Cf. A006880, A033844, A119780.

Cf. A099260, A274767 ((leading) digits of 103-digit a(100)).

Sequence in context: A264175 A187362 A176938 * A282735 A245252 A090251

Adjacent sequences: A006985 A006986 A006987 * A006989 A006990 A006991

Keyword

nonn,nice,changed

Author

N. J. A. Sloane, Robert G. Wilson v

Extensions

More terms from Paul Zimmermann

a(19) from Marc Deleglise, Jun 29 2008

a(20) found by Andrey V. Kulsha using a program by Xavier Gourdon, Oct 05 2011

a(21) from Henri Lifchitz, Sep 09 2014

a(22) from Henri Lifchitz, Nov 21 2014

Status

approved