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A110949 Integers n such that 4*10^n + 61 is prime. 0
1, 2, 7, 11, 191, 248, 1067, 2666, 5252, 13400, 22886, 23739, 29095 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

See Kamada link - primecount.txt for terms, primesize.txt for discovery details including probable or proved primes - search on "40061".

a(14) > 10^5. - Robert Price, Jan 22 2017

LINKS

Table of n, a(n) for n=1..13.

Makoto Kamada, List of near-repdigit-related prime numbers.

Index entries for primes involving repunits.

EXAMPLE

n = 7 is in the sequence because 4*10^7 + 61 = 4*10000000 + 61 = 40000000 + 61 = 40000061, which is prime.

PROG

(PARI) isok(n) = isprime(4*10^n+61); \\ Michel Marcus, Jan 22 2017

CROSSREFS

Cf. A049054, A088274, A088275, A095688, A107083, A108049, A108050, A108052, A108054.

Sequence in context: A069885 A069748 A064441 * A226703 A126343 A174539

Adjacent sequences:  A110946 A110947 A110948 * A110950 A110951 A110952

KEYWORD

more,nonn

AUTHOR

Julien Peter Benney (jpbenney(AT)ftml.net), Oct 04 2005

EXTENSIONS

a(9)-a(11) from Ray Chandler, Dec 23 2010

Prepended a(1)=1 by Robert Price, Jan 22 2017

a(12)-a(13) from Robert Price, Jan 22 2017

STATUS

approved

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Last modified January 28 00:32 EST 2020. Contains 331313 sequences. (Running on oeis4.)