A100360 Duplicate of A061421.
2, 7, 71, 110427941548649020598956093796432407239217743554726184882600387580788973
Offset: 1
This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
A100361:=n->`if`(isprime(2^n-n+1), n, NULL): seq(A100361(n), n=0..10^3); # Wesley Ivan Hurt, Oct 13 2014
{ta={{0}}, tb={{0}}};Do[g=n;s=2^n-n+1; If[PrimeQ[s], Print[n];ta=Append[ta, n]; tb=Append[tb, s]], {n, 1, 10000}];{ta, tb, g}
is(n)=ispseudoprime(2^n-n+1) \\ Charles R Greathouse IV, Feb 20 2017
is(n)=isprime(2^(n-1)+n) \\ Charles R Greathouse IV, May 22 2017
Select[Table[3^n + n + 1, {n, 0, 150}], PrimeQ] (* T. D. Noe, Apr 25 2012 *)
Select[Array[3^#+2^#+#+1&,2*6! ],PrimeQ[ # ]&]
65 = 2^6 + 1 is a term because 65 + 6 = 71 (prime).
[2^n + 1: n in [0..600] | IsPrime(2^n + n + 1)]
2^# + 1 &@ Select[Range[0, 600], PrimeQ[2^# + # + 1] &] (* Michael De Vlieger, Jan 29 2016 *)
a:=n->`if`(isprime(4^k+k+1),4^k+k+1,NULL): seq(a(k),k=0..300); # Muniru A Asiru, Mar 25 2018
21 = 3 * 7 = 2^4 + 4 + 1
f[n_]:=Last/@FactorInteger[n]=={1,1};Select[Array[2^#+#+1&,140,0],f[ # ]&]
Select[Table[2^k+k+1,{k,0,200}],PrimeNu[#]==PrimeOmega[#]==2&] (* Harvey P. Dale, Jul 11 2023 *)
is(n) = my(f = factor(n), e = logint(n, 2)); f[,2] == [1, 1]~ && n == 1<David A. Corneth, May 27 2023
Comments