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A146964 a(n) = ((4 + sqrt(7))^n + (4 - sqrt(7))^n))/2. 2
1, 4, 23, 148, 977, 6484, 43079, 286276, 1902497, 12643492, 84025463, 558412276, 3711069041, 24662841844, 163903113383, 1089259330468, 7238946623297, 48108239012164, 319715392487639, 2124748988791636, 14120553377944337 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Binomial transform of A146963. Inverse binomial transform of A146965.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..300

FORMULA

From Philippe Deléham and Klaus Brockhaus, Nov 05 2008: (Start)

a(n) = 8*a(n-1) - 9*a(n-2); a(0)=1, a(1)=4.

G.f.: (1-4*x)/(1-8*x+9*x^2). (End)

a(n) = (Sum_{k=0..n} A098158(n,k)*4^(2*k)*7^(n-k))/4^n. - Philippe Deléham, Nov 06 2008

PROG

(MAGMA) Z<x>:= PolynomialRing(Integers()); N<r7>:=NumberField(x^2-7); S:=[ ((4+r7)^n+(4-r7)^n)/2: n in [0..20] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Nov 05 2008

CROSSREFS

Cf. A146963, A146965, A098158.

Sequence in context: A162561 A277921 A020079 * A194006 A116881 A107089

Adjacent sequences:  A146961 A146962 A146963 * A146965 A146966 A146967

KEYWORD

nonn

AUTHOR

Al Hakanson (hawkuu(AT)gmail.com), Nov 03 2008

EXTENSIONS

Extended beyond a(7) by Klaus Brockhaus, Nov 05 2008

Edited by Klaus Brockhaus, Jul 16 2009

STATUS

approved

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Last modified May 22 18:53 EDT 2019. Contains 323481 sequences. (Running on oeis4.)