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A164305
a(n) = 6*a(n-1) - 7*a(n-2) for n > 1; a(0) = 3, a(1) = 17.
3
3, 17, 81, 367, 1635, 7241, 32001, 141319, 623907, 2754209, 12157905, 53667967, 236902467, 1045739033, 4616116929, 20376528343, 89946351555, 397042410929, 1752630004689, 7736483151631, 34150488876963, 150747551200361, 665431885063425, 2937358451978023
OFFSET
0,1
COMMENTS
Binomial transform of A164304. Third binomial transform of A164654. Inverse binomial transform of A164535.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000 (terms 0..169 from Vincenzo Librandi)
FORMULA
a(n) = 6*a(n-1) - 7*a(n-2) for n > 1; a(0) = 3, a(1) = 17.
G.f.: (3-x)/(1-6*x+7*x^2).
a(n) = ((3+4*sqrt(2))*(3+sqrt(2))^n + (3-4*sqrt(2))*(3-sqrt(2))^n)/2.
E.g.f.: (3*cosh(sqrt(2)*x) + 4*sqrt(2)*sinh(sqrt(2)*x))*exp(3*x). - G. C. Greubel, Sep 13 2017
MATHEMATICA
LinearRecurrence[{6, -7}, {3, 17}, 30] (* Harvey P. Dale, Jun 03 2015 *)
PROG
(Magma) Z<x>:=PolynomialRing(Integers()); N<r>:=NumberField(x^2-2); S:=[ ((3+4*r)*(3+r)^n+(3-4*r)*(3-r)^n)/2: n in [0..21] ]; [ Integers()!S[j]: j in [1..#S] ]; // Klaus Brockhaus, Aug 20 2009
(PARI) x='x+O('x^50); Vec((3-x)/(1-6*x+7*x^2)) \\ G. C. Greubel, Sep 13 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Al Hakanson (hawkuu(AT)gmail.com), Aug 12 2009
EXTENSIONS
Edited and extended beyond a(5) by Klaus Brockhaus, Aug 20 2009
STATUS
approved