This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A105447 #3 Mar 30 2012 18:40:28 %S A105447 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 A105447 39,42,47,50,52,53,54,56,57,58,60,63,68,76,81,84,86,87,88,90,91,92,94, %U A105447 97,102,110,123,131,139,141,142,143,145,146,147,149,152,157 %N A105447 Positive integers whose representation as Roman Fibonacci numbers has exactly two symbols. %F A105447 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 A105447 In Roman Fibonacci number representation: %e A105447 4 = "22", 6 = "33", 7 = "52", 9 = "81", 10 = "55", 11 = "83", 12 = "1A", %e A105447 14 = "A1", 15 = "A2", 16 = "88", 18 = "3B", 19 = "2B", 20 = "1B", ... %e A105447 143 = "1F", 145 = "F1", 146 = "F2", 147 = "F3", 149 = "F5", 152 = "F8". %Y A105447 Cf. A000045, A006968, A105446, A105448-A105455. %K A105447 base,easy,nonn %O A105447 1,1 %A A105447 _Jonathan Vos Post_, Apr 09 2005