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A185949 Smallest prime ending in 10^n+1 in its base-10 representation. 1
11, 101, 21001, 1810001, 2100001, 61000001, 2010000001, 11100000001, 61000000001, 1810000000001, 14100000000001, 151000000000001, 5010000000000001, 9100000000000001, 271000000000000001, 1110000000000000001, 24100000000000000001, 261000000000000000001, 3910000000000000000001, 11100000000000000000001 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..995

MAPLE

f:= proc(n) local p;

  for p from 10^n+1 by 10^(n+1) do

    if isprime(p) then return p fi

  od

end proc:

map(f, [$1..30]); # Robert Israel, May 03 2018

MATHEMATICA

Table[k=0; While[!PrimeQ[p=FromDigits[Join[IntegerDigits[k], IntegerDigits[10^n+1]]]], k++]; p, {n, 20}]

PROG

(Python)

# This implementation assumes function is_prime(n)

# returns True if n is prime, or False otherwise:

for n in range (1, 100):

....pattern = 10**n + 1

....for j in range (0, 10000000):

........if (j == 0):

............num = "%d" % (pattern)

........else:

............num = "%d%d" % (j, pattern)

........if (is_prime(num)):

............print num

............break

CROSSREFS

Sequence in context: A199304 A156668 A103992 * A001387 A247863 A180280

Adjacent sequences:  A185946 A185947 A185948 * A185950 A185951 A185952

KEYWORD

nonn,base

AUTHOR

Amir H. Farrahi, Feb 07 2011

STATUS

approved

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Last modified April 19 06:30 EDT 2019. Contains 322237 sequences. (Running on oeis4.)