A173928 - OEIS

%I #3 Mar 30 2012 18:52:39

%S 0,1,1,7,13,19,19,17,31,5,47,53,47,61,41,67,1,31,47,113,103,79,113,27,

%T 73,149,155,57,139,21,37,161,227,211,211,1,337,245,41,117,413,241,337,

%U 13,79,451,421,47,181,511,311,323,423,299,545,269,565,211

%N a(n+2)=A162488(n)-A162489(n) where a(1)=0 and a(2)=1.

%C 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).

%e 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.

%Y Cf. A094133, A162488, A162489.

%K nonn

%O 1,4

%A _Juri-Stepan Gerasimov_, Mar 02 2010

%E a(30) and a(32) corrected by _R. J. Mathar_, Mar 09 2010