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A270339 Numbers k such that (11*10^k + 19)/3 is prime. 502
1, 2, 3, 9, 17, 18, 20, 24, 29, 36, 48, 114, 126, 135, 153, 170, 241, 363, 483, 579, 681, 948, 2483, 2798, 3081, 5137, 5640, 6890, 7080, 12600, 16929, 24253, 24793, 35546, 52956, 69645, 133831 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
For k>1, numbers such that the digit 3 followed by k-2 occurrences of the digit 6 followed by the digits 73 is prime (see Example section).
a(38) > 2*10^5.
LINKS
Makoto Kamada, Search for 36w73.
EXAMPLE
3 is in this sequence because (11*10^3 + 19)/3 = 3673 is prime.
Initial terms and primes associated:
a(1) = 1, 43;
a(2) = 2, 373;
a(3) = 3, 3673;
a(4) = 9, 3666666673;
a(5) = 17, 366666666666666673, etc.
MATHEMATICA
Select[Range[0, 100000], PrimeQ[(11*10^# + 19)/3] &]
PROG
(PARI) is(n)=isprime((11*10^n + 19)/3) \\ Charles R Greathouse IV, Mar 16 2016
CROSSREFS
Sequence in context: A086771 A156066 A143890 * A272057 A056658 A302164
KEYWORD
nonn,more
AUTHOR
Robert Price, Mar 15 2016
EXTENSIONS
a(37) from Robert Price, Sep 16 2018
STATUS
approved

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Last modified March 28 14:13 EDT 2024. Contains 371254 sequences. (Running on oeis4.)