Hexagonal Fibonacci
y.kohmoto
zbi74583 at boat.zero.ad.jp
Fri Jun 18 07:16:54 CEST 2004
Hello, seqfans.
I considerd the same kind of generalized Fibonacci as A094767
http://www.research.att.com/cgi-bin/access.cgi/as/njas/sequences/eisA.cgi?An
um=A094767
To Neil :
If they are good, add them on OEIS.
Yasutoshi
%I A000001
%S A000001 1, 1, 2, 4, 7, 12, 20, 34, 55, 90, 148, 240, 394, 638
%N A000001 A hexagonal spiral Fibonacci sequence
%C A000001 Consider the following spiral :
%C A000001 a(6) a(7) a(8)
%C A000001 a(5) a(1) a(2) a(9)
%C A000001 a(14) a(4) a(3) a(10)
%C A000001 a(13) a(12) a(11)
%C A000001 Then
%C A000001 a(1)=1 , a(n)=a(n-1)+Sum{a(i) : a(i) adjacent to a(n-1)}
%C A000001 Here 6 terms around a(m) touch a(m).
%C A000001 then a(n) satisfies
%C A000001 a(2)=a(1) =1
%C A000001 a(3)=a(1)+a(2) =2
%C A000001 a(4)=a(1)+a(2)+a(3) =4
%C A000001 a(5)=a(1)+a(3)+a(4) =7
%C A000001 a(6)=a(1)+a(4)+a(5) =12
%C A000001 a(7)=a(1)+a(5)+a(6) =20
%C A000001 table :
%C A000001 12 20 34
%C A000001 7 1 1 55
%C A000001 638 4 2 90
%C A000001 394 240 148
%K A000001 nonn
%O A000001 1, 3
%A A000001 Yasutoshi Kohmoto (zbi74583 at boat.zero.ad.jp)
%Y A000001 A000002
%I A000002
%S A000002 0, 1, 1, 2, 3, 5, 8, 14, 23, 38, 63, 102,168, 272
%N A000002 A hexagonal spiral Fibonacci sequence
%C A000002 Consider the following spiral :
%C A000002 a(6) a(7) a(8)
%C A000002 a(5) a(1) a(2) a(9)
%C A000002 a(14) a(4) a(3) a(10)
%C A000002 a(13) a(12) a(11)
%C A000002 Then
%C A000002 a(1)=0 , a(2)=1, a(n)=a(n-1)+Sum{a(i) , a(i) is adjacent to
a(n-1)}
%C A000002 6 terms around a(m) touch a(m).
%C A000002 table :
%C A000002 5 8 14
%C A000002 3 0 1 23
%C A000002 272 2 1 38
%C A000002 168 102 63
%K A000002 nonn
%O A000002 0, 4
%A A000002 Yasutoshi Kohmoto (zbi74583 at boat.zero.ad.jp)
%Y A000002 A000001
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