

A041421


Denominators of continued fraction convergents to sqrt(226).


3



1, 30, 901, 27060, 812701, 24408090, 733055401, 22016070120, 661215159001, 19858470840150, 596415340363501, 17912318681745180, 537965975792718901, 16156891592463312210, 485244713749692085201, 14573498304083225868240
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OFFSET

0,2


COMMENTS

Also called the 30metallonacci sequence; the g.f. 1/(1k*xx^2) gives the kmetallonacci sequence.
a(n) is the number of tilings of an nboard (a board with dimensions n X 1) using unit squares and dominoes (with dimensions 2 X 1) if there are 30 kinds of squares available. (End)


LINKS



FORMULA

a(n) = F(n, 30), the nth Fibonacci polynomial evaluated at x=30.  T. D. Noe, Jan 19 2006
a(n) = 30*a(n1) + a(n2) for n > 1; a(0)=1, a(1)=30.
G.f.: 1/(130*xx^2). (End)


MATHEMATICA

LinearRecurrence[{30, 1}, {1, 30}, 20] (* Harvey P. Dale, Jun 30 2022 *)


CROSSREFS



KEYWORD

nonn,frac,easy


AUTHOR



EXTENSIONS



STATUS

approved



