OFFSET
1,1
COMMENTS
There are 4! = 24 permutations of 4 elements, because of commutativity of |x|=|- x| sequence has 4!/2 = 12 different terms.
Note that two terms of sequence (3 and 311) are prime numbers.
REFERENCES
Ivan Niven und H. S. Zuckermann, Einfuehrung in die Zahlentheorie, B.I. Mannheim 1976
Friedhelm Padberg, Elementare Zahlentheorie, Spektrum Akademischer Verlag, 2. Auflage 1991
EXAMPLE
(1) 3 = 2^7 - 5^3 = prime(2)
(2) 76 = 2 ^ 2 x 19 = 5^3 - 7^2
(3) 115 = 5 x 23 = 3^5 - 2^7
(4) 194 = 2 x 97 = 3^5 - 7^2
(5) 311 = 7^3 - 2^5 = prime(2^6)
(6) 318 = 2 x 3 x 53 = 7^3 - 5^2
(7) 2155 = 5 x 431 = 3^7 - 2^5
(8) 2162 = 2 x 23 x 47 = 3^7 - 5^2
(9) 16798 = 2 x 37 x 227 = 7^5 - 3^2
(10) 16799 = 107 x 157 = 7^5 - 2^3
(11) 78116 = 2 ^ 2 x 59 x 331 = 5^7 - 3^2
(12) 78117 = 3 x 13 x 2003 = 5^7 - 2^3
CROSSREFS
KEYWORD
fini,full,nonn
AUTHOR
Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Nov 24 2009
STATUS
approved