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A081071 Lucas(4n+2)-2, or Lucas(2n+1)^2. 2
1, 16, 121, 841, 5776, 39601, 271441, 1860496, 12752041, 87403801, 599074576, 4106118241, 28143753121, 192900153616, 1322157322201, 9062201101801, 62113250390416, 425730551631121, 2918000611027441, 20000273725560976 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

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)=-2+(3/2)*{[(7/2)-(3/2)*sqrt(5)]^n+[(7/2)+(3/2)*sqrt(5)]^n}+(1/2)*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

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 40 do printf(`%d, `, luc(4*n+2)-2) od:

CROSSREFS

Cf. A000032 (Lucas numbers).

Sequence in context: A082921 A191902 A014765 * A069658 A069667 A104265

Adjacent sequences:  A081068 A081069 A081070 * A081072 A081073 A081074

KEYWORD

nonn,easy

AUTHOR

R. K. Guy (rkg(AT)cpsc.ucalgary.ca), Mar 04, 2003

EXTENSIONS

More terms and Maple code from James A. Sellers (sellersj(AT)math.psu.edu), Mar 05, 2003

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Last modified February 15 03:11 EST 2012. Contains 205694 sequences.