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A173928
a(n+2)=A162488(n)-A162489(n) where a(1)=0 and a(2)=1.
0
0, 1, 1, 7, 13, 19, 19, 17, 31, 5, 47, 53, 47, 61, 41, 67, 1, 31, 47, 113, 103, 79, 113, 27, 73, 149, 155, 57, 139, 21, 37, 161, 227, 211, 211, 1, 337, 245, 41, 117, 413, 241, 337, 13, 79, 451, 421, 47, 181, 511, 311, 323, 423, 299, 545, 269, 565, 211
OFFSET
1,4
COMMENTS
Where A162488 are numbers x such that x^y+y^x is prime, for some y>1, y<x and A162489 is least y such that x^y+y^x is prime, for x=A162488(n).
EXAMPLE
a(1)=0 because 1^1+1^1=2=prime and 0=1-1; a(2)=1 because 1^2+2^1=3=prime and 1=2-1; a(3)=1 because 2^3+3^2 and 1=3-2; a(4)=7 because 2^9+9^2 and 7=9-2.
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
a(30) and a(32) corrected by R. J. Mathar, Mar 09 2010
STATUS
approved