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A104335
Positive integers n such that n^14 + 1 is semiprime (A001358).
13
4, 74, 94, 116, 270, 464, 556, 654, 1140, 1156, 1246, 1306, 1736, 2464, 2470, 2604, 2804, 2836, 2900, 3054, 3890, 4006, 4056, 4330, 4736, 4780, 5016, 5294, 5340, 5486, 5700, 5834, 6434, 7114, 7304, 8626, 8880, 9164, 9546, 9744, 9980, 10086, 10166
OFFSET
1,1
COMMENTS
x^14+1 has factors (1 + x^2) (1 - x^2 + x^4 - x^6 + x^8 - x^10 + x^12).
LINKS
EXAMPLE
4^14 + 1 = 268435457 = 17 * 15790321,
74^14 + 1 = 147653612273582215982104577 = 5477 * 26958848324553992328301,
1140^14 + 1 = 6261349103849104148619671961600000000000001 = 1299601 * 4817901112610027345792802530622860401.
MATHEMATICA
Select[ Range[2, 10422, 2], PrimeQ[ #^2 + 1] && PrimeQ[ #^12 - #^10 + #^8 - #^6 + #^4 - #^2 + 1] &] (*Robert G. Wilson v, Apr 18 2005 *)
Select[Range[2, 10200, 2], PrimeOmega[#^14+1]==2&] (* Harvey P. Dale, Oct 16 2011 *)
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Apr 17 2005
EXTENSIONS
More terms from Robert G. Wilson v, Apr 18 2005
STATUS
approved