|
Search: id:A081015
|
|
|
| A081015 |
|
Lucas(4n+3)+1, or 5*Fibonacci(2n+1)*Fibonacci(2n+2). |
|
+0
2
|
|
| 5, 30, 200, 1365, 9350, 64080, 439205, 3010350, 20633240, 141422325, 969323030, 6643838880, 45537549125, 312119004990, 2139295485800, 14662949395605, 100501350283430, 688846502588400, 4721424167835365, 32361122672259150
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
REFERENCES
|
Hugh C. Williams, Edouard Lucas and Primality Testing, John Wiley and Sons, 1998, p. 75
|
|
FORMULA
|
a(n) = 8a(n-1)-8a(n-2)+a(n-3)
a(n)=1+2*{[(7/2)-(3/2)*sqrt(5)]^n+[(7/2)+(3/2)*sqrt(5)]^n}+sqrt(5)*{[(7/2)+(3/2)*sqrt(5)]^n-[(7/2)-(3/2)*sqrt(5)]^n}, with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Dec 01 2008]
|
|
MAPLE
|
luc := proc(n) option remember: if n=0 then RETURN(2) fi: if n=1 then RETURN(1) fi: luc(n-1)+luc(n-2): end: for n from 0 to 25 do printf(`%d, `, luc(4*n+3)+1) od:
|
|
CROSSREFS
|
Cf. A000045 (Fibonacci numbers), A000032 (Lucas numbers).
Sequence in context: A158828 A034164 A103433 this_sequence A090139 A107265 A128328
Adjacent sequences: A081012 A081013 A081014 this_sequence A081016 A081017 A081018
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
R. K. Guy (rkg(AT)cpsc.ucalgary.ca), Mar 01, 2003
|
|
EXTENSIONS
|
More terms and Maple code from James A. Sellers (sellersj(AT)math.psu.edu), Mar 03, 2003
|
|
|
Search completed in 0.002 seconds
|
