|
| |
|
|
A081006
|
|
Fibonacci(4n)-1, or Fibonacci(2n+1)*Lucas(2n-1).
|
|
1
| |
|
|
2, 20, 143, 986, 6764, 46367, 317810, 2178308, 14930351, 102334154, 701408732, 4807526975, 32951280098, 225851433716, 1548008755919, 10610209857722, 72723460248140, 498454011879263, 3416454622906706, 23416728348467684, 160500643816367087
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| Apart from the offset, the same as A003481. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 18 2008]
|
|
|
REFERENCES
| Hugh C. Williams, Edouard Lucas and Primality Testing, John Wiley and Sons, 1998, p. 75
|
|
|
LINKS
| Nathaniel Johnston, Table of n, a(n) for n = 1..500
|
|
|
FORMULA
| a(n) = 8a(n-1)-8a(n-2)+a(n-3)
a(n)=-1+(3/2)*{[(7/2)-(3/2)*sqrt(5)]^n+[(7/2)+(3/2)*sqrt(5)]^n}+(7/10)*sqrt(5)*{[(7/2)+(3 /2)*sqrt(5)]^n-[(7/2)-(3/2)*sqrt(5)]^n}, with n>=0 [From Paolo P. Lava (paoloplava(AT)gmail.com), Dec 01 2008]
|
|
|
MAPLE
| with(combinat) for n from 0 to 25 do printf(`%d, `, fibonacci(4*n)-1) od
|
|
|
PROG
| (MAGMA) [Fibonacci(4*n)-1: n in [1..100]]; // Vincenzo Librandi, Apr 15 2011
|
|
|
CROSSREFS
| Cf. A000045 (Fibonacci numbers), A000032 (Lucas numbers).
Sequence in context: A093647 A003490 A003481 * A000183 A198052 A203216
Adjacent sequences: A081003 A081004 A081005 * A081007 A081008 A081009
|
|
|
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
|
| |
|
|
