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a(n) = (10^n)-th prime.
(Formerly M2151)
46

%I M2151 #96 Apr 03 2023 10:36:09

%S 2,29,541,7919,104729,1299709,15485863,179424673,2038074743,

%T 22801763489,252097800623,2760727302517,29996224275833,

%U 323780508946331,3475385758524527,37124508045065437,394906913903735329,4185296581467695669,44211790234832169331

%N a(n) = (10^n)-th prime.

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

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

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

%H Marc Deleglise et al., <a href="/A006988/b006988.txt">Table of n, a(n) for n = 0..24</a> (a(23) corrected and a(24) added using Kim Walisch's primecount program, by David Baugh, Nov 11 2015)

%H C. K. Caldwell, <a href="http://www.utm.edu/research/primes/notes/md.html">Marc Deleglise's work on new values of pi(x)</a>

%H UTM, <a href="https://t5k.org/nthprime/">The Nth Prime Page</a>.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PrimeNumber.html">Prime Number</a>

%H R. G. Wilson, V, <a href="/A002982/a002982.pdf">Letter to N. J. A. Sloane, Jan. 1989</a>

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

%p A006988:=n->ithprime(10^n): seq(A006988(n), n=0..7); # _Wesley Ivan Hurt_, Nov 21 2014

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

%o (PARI) a(n)=prime(10^n) \\ _Charles R Greathouse IV_, Jul 21 2011

%Y Cf. A006880, A033844, A119780.

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

%K nonn,nice

%O 0,1

%A _N. J. A. Sloane_, _Robert G. Wilson v_

%E More terms from _Paul Zimmermann_

%E a(19) from _Marc Deleglise_, Jun 29 2008

%E a(20) found by _Andrey V. Kulsha_ using a program by Xavier Gourdon, Oct 05 2011

%E a(21) from _Henri Lifchitz_, Sep 09 2014

%E a(22) from _Henri Lifchitz_, Nov 21 2014