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A084135 a(n)=10a(n-1)-15a(n-2), a(0)=1,a(1)=5. 1
1, 5, 35, 275, 2225, 18125, 147875, 1206875, 9850625, 80403125, 656271875, 5356671875, 43722640625, 356876328125, 2912923671875, 23776091796875, 194067062890625, 1584029251953125, 12929286576171875, 105532426982421875 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Binomial transform of A084134.

LINKS

Table of n, a(n) for n=0..19.

Index entries for linear recurrences with constant coefficients, signature (10, -15).

FORMULA

a(n)=(5+sqrt(10))^n/2+(5-sqrt(10))^n/2; G.f.: (1-5x)/(1-10x+15x^2); E.g.f. : exp(5x)cosh(sqrt(10)x).

MATHEMATICA

LinearRecurrence[{10, -15}, {1, 5}, 30] (* Harvey P. Dale, Oct 10 2012 *)

PROG

(PARI) a(n)=if(n<0, 0, polsym(x^2-10*x+15, n)[1+n]/2)

CROSSREFS

Sequence in context: A292839 A180900 A087630 * A229111 A138233 A322666

Adjacent sequences:  A084132 A084133 A084134 * A084136 A084137 A084138

KEYWORD

easy,nonn

AUTHOR

Paul Barry, May 16 2003

STATUS

approved

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Last modified November 17 15:59 EST 2019. Contains 329235 sequences. (Running on oeis4.)