OFFSET
1,1
COMMENTS
a(5) has 311 digits. - Harvey P. Dale, Mar 18 2019
Using the above, a(5) = 1 + 2^399 + 4^399 + 6^399. - David A. Corneth, Mar 18 2019
EXAMPLE
n=1: 1 + 2 + 4 + 6 = 13 is prime.
MATHEMATICA
Do[s=1^w+2^w+4^w+6^w; If[IntegerQ[w/100], Print[{w}]]; If[PrimeQ[s], Print[{w, s}]], {w, 0, 1000}]
Select[Table[1+2^n+4^n+6^n, {n, 60}], PrimeQ] (* Harvey P. Dale, Mar 18 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Apr 15 2003
STATUS
approved