A003617 Smallest n-digit prime. (Formerly M2008)

2, 11, 101, 1009, 10007, 100003, 1000003, 10000019, 100000007, 1000000007, 10000000019, 100000000003, 1000000000039, 10000000000037, 100000000000031, 1000000000000037, 10000000000000061, 100000000000000003, 1000000000000000003, 10000000000000000051

Offset

1,1

References

O'Hara, J. Rec. Math., 22 (1990), Table on page 278.

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

Links

Giovanni Resta, Table of n, a(n) for n = 1..1000 (terms 1..200 from T. D. Noe. Jon E. Schoenfield used Magma to verify that terms 1..200 are primes, Jan 31 2009)

Eric Weisstein's World of Mathematics, Next Prime

R. G. Wilson, v., Extract from letter to N. J. A. Sloane, May 20 1994, with annotated scanned copy of page 278 of O'Hara article.

Maple

a:= n-> nextprime(10^(n-1)):
seq(a(n), n=1..20);  # Alois P. Heinz, Feb 11 2021

Mathematica

Table[a := 10^n + 1; While[ ! PrimeQ[a], a++ ]; a, {n, 0, 30}] (* Stefan Steinerberger, Apr 08 2006 *)
NextPrime/@(10^Range[0, 20])  (* Harvey P. Dale, May 01 2011 *)

Prog

(PARI) a(n)=nextprime(10^(n-1)) \\ Charles R Greathouse IV, Jul 15 2011
(Python)
from sympy import nextprime
print([nextprime(10**(n-1)) for n in range(1, 21)]) # Michael S. Branicky, Feb 11 2021

Crossrefs

Cf. A003618, A033873.

Sequence in context: A115062 A062397 A158578 * A114018 A089770 A249447

Adjacent sequences: A003614 A003615 A003616 * A003618 A003619 A003620

Keyword

nonn,nice,base,changed

Author

N. J. A. Sloane, Mira Bernstein

Extensions

More terms from Stefan Steinerberger, Apr 08 2006

Status

approved