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A155628 7^n-4^n+1^n 21
1, 4, 34, 280, 2146, 15784, 113554, 807160, 5699266, 40091464, 281426674, 1973132440, 13824509986, 96821901544, 677954637394, 4746487768120, 33228635602306, 232613334118024, 1628344878433714, 11398620307466200 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

Index entries for linear recurrences with constant coefficients, signature (12,-39,28).

FORMULA

G.f.: 1/(1-7*x)-1/(1-4*x)+1/(1-x). E.g.f.: e^(7*x)-e^(4*x)+e^x.

a(n)=11*a(n-1)-28*a(n-2)+18 with a(0)=1, a(1)=4 - Vincenzo Librandi, Jul 21 2010

MATHEMATICA

Table[7^n-4^n+1, {n, 0, 20}] (* or *) LinearRecurrence[{12, -39, 28}, {1, 4, 34}, 20] (* Harvey P. Dale, Jul 16 2017 *)

PROG

(PARI) a(n)=7^n-4^n+1 \\ Charles R Greathouse IV, Sep 24 2015

CROSSREFS

Cf. A155596, A155597, A155598, A155599, A155600, A155601, A155622, A155623, A155624, A155625, A155626, A155627.

Sequence in context: A116430 A216239 A201684 * A036352 A005569 A232910

Adjacent sequences:  A155625 A155626 A155627 * A155629 A155630 A155631

KEYWORD

nonn,easy

AUTHOR

Mohammad K. Azarian, Jan 30 2009

STATUS

approved

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Last modified November 19 03:48 EST 2019. Contains 329310 sequences. (Running on oeis4.)