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A262195 Primes that are the concatenation 1, k! and 1, for some integer k. 0
150401, 13628801, 136288001, 113076743680001 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Inspired by A089764.

LINKS

Table of n, a(n) for n=1..4.

EXAMPLE

For n = 1, k = 7, 7! = 5040, and a(1) = 150401 is a prime number.

MATHEMATICA

Select[Table[FromDigits[Flatten[{(1), IntegerDigits[n!], {1}}]], {n, 1000}], PrimeQ] (* Vincenzo Librandi, Sep 15 2015 *)

PROG

(PARI) for(n=1, 1e3, if(isprime(k=eval(Str(1, n!, 1))), print1(k", ")))

(MAGMA) [m: n in [1..1000] | IsPrime(m) where m is Seqint(Intseq(1) cat Intseq(Factorial(n)) cat Intseq(1))]; // Vincenzo Librandi, Sep 15 2015

CROSSREFS

Cf. A089764.

Sequence in context: A254239 A051651 A065324 * A138264 A343679 A246285

Adjacent sequences:  A262192 A262193 A262194 * A262196 A262197 A262198

KEYWORD

nonn,hard,base

AUTHOR

Altug Alkan, Sep 14 2015

STATUS

approved

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Last modified January 23 13:57 EST 2022. Contains 350511 sequences. (Running on oeis4.)