The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A007223 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A007223

Number of distinct perforation patterns for deriving (v,b) = (n+2,n) punctured convolutional codes from (2,1).
(history; published version)

#49 by Michel Marcus at Sun Apr 30 07:10:14 EDT 2023

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reviewed

approved

#48 by Joerg Arndt at Sun Apr 30 06:55:07 EDT 2023

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proposed

reviewed

#47 by Jean-François Alcover at Sun Apr 30 04:31:43 EDT 2023

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editing

proposed

#46 by Jean-François Alcover at Sun Apr 30 04:31:03 EDT 2023

MATHEMATICA

A[x_] = (1 - Sqrt[1 - 4x])/(2x) - 1;

CoefficientList[(A[x]^2 + A[x^2])/(2 x^2) + O[x]^25, x] (* Jean-François Alcover, Apr 30 2023, after R. J. Mathar's proven conjecture *)

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approved

editing

#45 by R. J. Mathar at Sun Mar 21 10:14:56 EDT 2021

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proposed

approved

#44 by R. J. Mathar at Sun Mar 21 06:55:08 EDT 2021

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editing

proposed

#43 by R. J. Mathar at Sun Mar 21 06:53:51 EDT 2021

FORMULA

D-finite with recurrence -(11*n-30)*(n+2)*(n+1) *a(n) +10*(n+1) *(7*n^2-22*n+6) *a(n-1) -60*(n-2)*(n^2-5*n+1) *a(n-2) -40*(n-2) *(7*n^2-22*n+6) *a(n-3) +16*(2*n-7) *(n-3) *(13*n-22) *a(n-4)=0. - R. J. Mathar, Mar 21 2021

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approved

editing

#42 by Alois P. Heinz at Wed Aug 05 19:27:12 EDT 2020

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reviewed

approved

#41 by Peter Luschny at Wed Aug 05 13:49:49 EDT 2020

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proposed

reviewed

#40 by Petros Hadjicostas at Mon Jul 27 17:16:42 EDT 2020

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editing

proposed