A059915 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.

23, 139, 211, 422, 461, 761

Offset

0,1

Comments

The sequence given above contains all non-F-numbers up to 5000000 (according to Klaus Nagel (nagel.klaus(AT)t-online.de)).

Links

Table of n, a(n) for n=0..5.

Example

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.

Crossrefs

Sequence in context: A160221 A042024 A141999 * A059701 A226680 A307660

Adjacent sequences: A059912 A059913 A059914 * A059916 A059917 A059918

Keyword

hard,more,nonn

Author

Christian Wieschebrink (wieschebrink(AT)t-online.de), Feb 28 2001

Status

approved