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Revision History for A134172

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Showing entries 1-10 | older changes
Expansion of x^2*(1+x)*(1-x+x^2) / ((1-x)^2*(1+x^2)^2).
(history; published version)
#14 by Joerg Arndt at Mon May 30 06:57:55 EDT 2016
STATUS

editing

approved

#13 by Joerg Arndt at Mon May 30 06:57:45 EDT 2016
EXTENSIONS

Definition uses New name using the g.f. of _from _Colin Barker_, May 30 2016

STATUS

proposed

editing

#12 by Michel Marcus at Mon May 30 06:51:15 EDT 2016
STATUS

editing

proposed

Discussion
Mon May 30
06:57
Joerg Arndt: Thanks!
#11 by Michel Marcus at Mon May 30 06:51:10 EDT 2016
EXTENSIONS

Definition uses the g.f. of _Colin Barker._, May 30 2016

STATUS

proposed

editing

#10 by Bruno Berselli at Mon May 30 06:49:39 EDT 2016
STATUS

editing

proposed

#9 by Bruno Berselli at Mon May 30 06:49:26 EDT 2016
LINKS

<a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (2, -3, 4, -3, 2, -1).

#8 by Bruno Berselli at Mon May 30 06:48:35 EDT 2016
NAME

Starting with 0, 1, 2, 3, ... (A001477), write 0, 0 instead of a(0), 1, 1 instead of a(3) and in general n, n instead of a(3n).

Expansion of x^2*(1+x)*(1-x+x^2) / ((1-x)^2*(1+x^2)^2).

COMMENTS

Old definition was: "Starting with 0, 1, 2, 3, ... (A001477), write 0, 0 instead of a(0), 1, 1 instead of a(3) and in general n, n instead of a(3n)".

FORMULA

a(n) = (-2+(-i)^n+i^n+(4-(1+i)*(-i)^n-(1-i)*i^n)*n)/8 where i = sqrt(-1).

a(n) = 2*a(n-1)-3*a(n-2)+4*a(n-3)-3*a(n-4)+2*a(n-5)-a(n-6) for n>5.

a(n) = (-2+(-i)^n+i^n+(4-(1+i)*(-i)^n-(1-i)*i^n)*n)/8 where i = sqrt(-1).

a(n) = 2*a(n-1)-3*a(n-2)+4*a(n-3)-3*a(n-4)+2*a(n-5)-a(n-6) for n>5. (End)

EXTENSIONS

Definition uses the g.f. of Colin Barker.

STATUS

proposed

editing

#7 by Colin Barker at Mon May 30 06:40:38 EDT 2016
STATUS

editing

proposed

#6 by Colin Barker at Mon May 30 05:36:03 EDT 2016
FORMULA

From Colin Barker, May 30 2016: (Start)

a(n) = (-2+(-i)^n+i^n+(4-(1+i)*(-i)^n-(1-i)*i^n)*n)/8 where i = sqrt(-1).

a(n) = 2*a(n-1)-3*a(n-2)+4*a(n-3)-3*a(n-4)+2*a(n-5)-a(n-6) for n>5.

G.f.: x^2*(1+x)*(1-x+x^2) / ((1-x)^2*(1+x^2)^2).

(End)

PROG

(PARI) concat(vector(2), Vec(x^2*(1+x)*(1-x+x^2)/((1-x)^2*(1+x^2)^2) + O(x^50))) \\ Colin Barker, May 30 2016

KEYWORD

nonn,changed,easy

STATUS

proposed

editing

#5 by G. C. Greubel at Sun May 29 23:53:34 EDT 2016
STATUS

editing

proposed

Discussion
Mon May 30
00:25
Michel Marcus: Please see A134171
01:13
Michel Marcus: I did it
04:37
Joerg Arndt: Could we put a new name just using the g.f.?