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A097067 Expansion of (1-4*x+5*x^2)/(1-2*x)^2. 4
1, 0, 1, 4, 12, 32, 80, 192, 448, 1024, 2304, 5120, 11264, 24576, 53248, 114688, 245760, 524288, 1114112, 2359296, 4980736, 10485760, 22020096, 46137344, 96468992, 201326592, 419430400, 872415232, 1811939328, 3758096384 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Binomial transform of A097065. Binomial transform is (n-2)*2^(n-1)+2, or A048495 with an extra leading 1.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..2000

Index entries for linear recurrences with constant coefficients, signature (4,-4).

FORMULA

a(n) = (n-1)2^(n-2)+5*0^n/4; a(n) = 4*a(n-1)-4*a(n-2), n>1.

a(n+1) = A001787(n).

MAPLE

a:=n->abs(floor(sum (2^(n-1), j=1..n))): seq(a(n), n=-1..28); # Zerinvary Lajos, Jun 27 2007

PROG

(MAGMA) [(n-1)*2^(n-2)+5*0^n/4 : n in [0..30]]; // Vincenzo Librandi, Sep 25 2011

(PARI) Vec((1-4*x+5*x^2)/(1-2*x)^2 + O(x^50)) \\ Altug Alkan, Nov 13 2015

CROSSREFS

Essentially the same as A001787.

Sequence in context: A097392 A090634 A260186 * A139756 A085750 A001787

Adjacent sequences:  A097064 A097065 A097066 * A097068 A097069 A097070

KEYWORD

nonn,easy

AUTHOR

Paul Barry, Jul 22 2004

STATUS

approved

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Last modified February 15 16:25 EST 2019. Contains 320136 sequences. (Running on oeis4.)