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A147958 ((7+sqrt2)^n+(7-sqrt2)^n)/2 2
1, 7, 51, 385, 2993, 23807, 192627, 1577849, 13036417, 108350935, 904201491, 7566326929, 63431106929, 532418131343, 4472591813139, 37592633210825, 316085049734017, 2658336935367463, 22360719757645683, 188108240644768801 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

7th binomial transform of A077957 . Binomial transform of A147957 . Inverse binomial transform of A147959 . [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 30 2008]

FORMULA

a(n)=14*a(n-1)-47*a(n-2), n>1 ; a(0)=1, a(1)=7 . G.f.: (1-7x)/(1-14x+47x^2). a(n)=(Sum_{k, 0<=k<=n} A098158(n,k)*7^(2k)*2^(n-k))/7^n. [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 19 2008]

EXAMPLE

a(3)=385

PROG

(MAGMA) Z<x>:= PolynomialRing(Integers()); N<r2>:=NumberField(x^2-2); S:=[ ((7+r2)^n+(7-r2)^n)/2: n in [0..19] ]; [ Integers()!S[j]: j in [1..#S] ]; [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Nov 19 2008]

CROSSREFS

Sequence in context: A015555 A137382 A162757 * A104454 A019472 A081216

Adjacent sequences:  A147955 A147956 A147957 * A147959 A147960 A147961

KEYWORD

nonn

AUTHOR

Al Hakanson (hawkuu(AT)gmail.com), Nov 17 2008

EXTENSIONS

Extended beyond a(6) by Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Nov 19 2008

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Last modified February 14 11:36 EST 2012. Contains 205623 sequences.