This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A245495 Primes of the form  n! - (n+1)! + (n+2)! + 1. 1

%I

%S 103,4441,36650881,5787936001,19702293811201,1075342687614074880001,

%T 8547762518578406446202880000001,

%U 59043709472234119545920159524322926688993280000000001,698533028148544417308552639358841460358000936394290829866303488000000000001

%N Primes of the form n! - (n+1)! + (n+2)! + 1.

%C The next term a(10) has 95 digits which is too large to show in data section.

%C a(16) has 1181 digits, hence not included in b-file.

%C Primes for indices 3, 5, 9, 11, 14, 20, 27, 41, 54, 65, 81, 83, 105, 315, 323, 515, ... - _Robert G. Wilson v_, Aug 07 2014

%H K. D. Bajpai, <a href="/A245495/b245495.txt">Table of n, a(n) for n = 1..15</a>

%e m = 3: m! - (m+1)! + (m+2)! + 1 = 103, which is prime, hence appears in the sequence.

%e m = 5: m! - (m+1)! + (m+2)! + 1 = 4441, which is prime, hence appears in the sequence.

%t Select[Table[n! - (n + 1)! + (n + 2)! + 1, {n, 200}], PrimeQ[#] &]

%o (PARI)

%o a(n) = p=n!-(n+1)!+(n+2)!+1;if(ispseudoprime(p),return(p))

%o n=1;while(n<100,if(a(n),print1(a(n),", "));n++) \\ _Derek Orr_, Jul 27 2014

%Y Cf. A000040, A049984, A049432.

%K nonn

%O 1,1

%A _K. D. Bajpai_, Jul 24 2014

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 December 7 05:14 EST 2019. Contains 329839 sequences. (Running on oeis4.)