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%I #4 Jul 15 2012 09:53:52
%S 23,139,211,422,461,761
%N A sequence f(n) of positive integers is called an F-sequence (in memory of Fibonacci) if it satisfies f(0)=0, f(1)=1, f(2)=2 and for all n > 2, either f(n) = f(n-1) + f(n-2) or f(n) = f(n-1) + f(n-3). A positive integer is called an F-number if it occurs in any F-sequence. Sequence gives numbers which are not F-numbers.
%C The sequence given above contains all non-F-numbers up to 5000000 (according to Klaus Nagel (nagel.klaus(AT)t-online.de)).
%e 22 IS an F-number because 0,1,2,2,3,5,7,10,15,22,... is an F-sequence. All Fibonacci-numbers are F-numbers.
%K hard,more,nonn
%O 0,1
%A Christian Wieschebrink (wieschebrink(AT)t-online.de), Feb 28 2001
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