A105447 - OEIS

%I #3 Mar 30 2012 18:40:28

%S 4,6,7,9,10,11,12,14,15,16,18,19,20,22,23,24,26,29,31,32,33,35,36,37,

%T 39,42,47,50,52,53,54,56,57,58,60,63,68,76,81,84,86,87,88,90,91,92,94,

%U 97,102,110,123,131,139,141,142,143,145,146,147,149,152,157

%N Positive integers whose representation as Roman Fibonacci numbers has exactly two symbols.

%F a(n) is an element of A105447 iff A105446(n) = 2. a(n) is the sum or difference of two Fibonacci numbers A000045 and a(n) is not itself a Fibonacci number A000045.

%e In Roman Fibonacci number representation:

%e 4 = "22", 6 = "33", 7 = "52", 9 = "81", 10 = "55", 11 = "83", 12 = "1A",

%e 14 = "A1", 15 = "A2", 16 = "88", 18 = "3B", 19 = "2B", 20 = "1B", ...

%e 143 = "1F", 145 = "F1", 146 = "F2", 147 = "F3", 149 = "F5", 152 = "F8".

%Y Cf. A000045, A006968, A105446, A105448-A105455.

%K base,easy,nonn

%O 1,1

%A _Jonathan Vos Post_, Apr 09 2005