A083587 - OEIS

A083587

a(n) = 4*3^n/3 - 5*0^n/6 - (n-1)2^(n-1).

1, 4, 10, 28, 84, 260, 812, 2532, 7852, 24196, 74124, 225956, 686060, 2076612, 6270796, 18902500, 56904108, 171138308, 514332428, 1544963364, 4639084396, 13926166084, 41797372620, 125431963748, 376379777324, 1129315492740

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OFFSET

0,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (7,-16,12).

FORMULA

G.f.: (-10*x^3+2*x^2+3*x-1)/((2*x-1)^2*(3*x-1)). - Harvey P. Dale, Dec 31 2014

MATHEMATICA

Join[{1}, LinearRecurrence[{7, -16, 12}, {4, 10, 28}, 30]] (* Harvey P. Dale, Dec 31 2014 *)

Join[{1}, Table[4 3^n / 3 - 5 0^n / 6 - (n-1) 2^(n-1), {n, 1, 40}]] (* Vincenzo Librandi, Jan 01 2015 *)

PROG

(Magma) [4*3^n/3-5*0^n/6-(n-1)*2^(n-1): n in [0..30]]; // Vincenzo Librandi, Jan 01 2015

CROSSREFS

Cf. A083588.

Sequence in context: A026123 A091468 A103457 * A228403 A061639 A243600

Adjacent sequences: A083584 A083585 A083586 * A083588 A083589 A083590

KEYWORD

easy,nonn

AUTHOR

Paul Barry, May 01 2003

STATUS

approved