The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A270102 Numbers n such that 3^n - n*2^n is prime. 2
 3, 4, 5, 7, 8, 10, 11, 23, 34, 62, 95, 128, 173, 251, 260, 464, 628, 1267, 1895, 2057, 2743, 5102, 7790, 49163 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE n = 4 is a term since 3^4 - 4*2^4 = 17 is prime. MAPLE A270102:=n->`if`(isprime(3^n-n*2^n), n, NULL): seq(A270102(n), n=1..2000); # Wesley Ivan Hurt, May 08 2016 MATHEMATICA Select[Range[1, 1000], PrimeQ[3^# - #*2^#] &] (* Vaclav Kotesovec, Mar 11 2016 *) PROG (MATLAB) if isprime(3^n - n*2^n) disp(n) end (Python) from gmpy2 import is_prime for n in range(5000):    if(is_prime(3**n-n*2**n)):print(n, end=", ") # Soumil Mandal, May 08 2016 (PARI) is(n)=ispseudoprime(3^n-n*2^n) \\ Charles R Greathouse IV, Jun 06 2017 CROSSREFS Cf. A057468, A270104. Sequence in context: A287127 A174681 A267650 * A026347 A187482 A285950 Adjacent sequences:  A270099 A270100 A270101 * A270103 A270104 A270105 KEYWORD nonn,more AUTHOR Vardan Semerjyan, Mar 11 2016 EXTENSIONS a(24) from Giovanni Resta, May 05 2016 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 August 1 17:43 EDT 2021. Contains 346402 sequences. (Running on oeis4.)