The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

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