The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A025569 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A025569

T(2n-1,n), where T is the array defined in A025564.
(history; published version)

#10 by N. J. A. Sloane at Fri Sep 13 22:10:37 EDT 2019

STATUS

proposed

approved

#9 by Michel Marcus at Sun Sep 08 04:11:51 EDT 2019

STATUS

editing

proposed

Discussion

Sun Sep 08

04:12

Michel Marcus: and with a(19) correction

04:16

Sean A. Irvine: I'm loathe to actually change it, because there is a whole bunch of other sequences with similar issue.   It's probably best just to leave the offsets and sequence names alone. It will be a "can of worms" if you try and fix it.

Mon Sep 09

03:36

Joerg Arndt: Clark should take care of this!

Fri Sep 13

22:10

N. J. A. Sloane: I agree Clark should take care of this. Who is going to ask him?

#8 by Michel Marcus at Sun Sep 08 04:11:20 EDT 2019

PROG

(PARI) T(n, k) = if( k<0 || k>2*n, 0, if(n==0, 1, polcoeff( (1 + x + x^2)^n, k)+ polcoeff( (1 + x + x^2)^(n-1), k-1)));

a(n) = T(2*n, n+1); \\ Michel Marcus, Sep 08 2019

STATUS

proposed

editing

Discussion

Sun Sep 08

04:11

Michel Marcus: I agree with T(2n,n+1) and offset 0 and 1st term 0

#7 by Michel Marcus at Sun Sep 08 01:04:03 EDT 2019

STATUS

editing

proposed

#6 by Michel Marcus at Sun Sep 08 01:03:59 EDT 2019

CROSSREFS

Cf. A025564.

STATUS

proposed

editing

#5 by Sean A. Irvine at Sat Sep 07 19:35:42 EDT 2019

STATUS

editing

proposed

#4 by Sean A. Irvine at Sat Sep 07 19:33:56 EDT 2019

DATA

1, 4, 22, 120, 665, 3732, 21153, 120835, 694590, 4013088, 23284424, 135580865, 791862354, 4637009300, 27215510265, 160053426720, 942939231825, 5564024727096, 3878367902380, 32878367902380, 194530139772844, 1152303896900338, 6832908809693304, 40556775927067299, 240938382783554100

EXTENSIONS

a(19) corrected and more terms from Sean A. Irvine, Sep 07 2019

STATUS

approved

editing

Discussion

Sat Sep 07

19:35

Sean A. Irvine: Actually, the offset and formula looks wrong to me, perhaps due to older offset change in A025564.  It is more like T(2n,n+1), except for a(1).

#3 by Russ Cox at Fri Mar 30 18:56:04 EDT 2012

AUTHOR

Clark Kimberling (ck6(AT)evansville.edu)

Clark Kimberling

Discussion

Fri Mar 30

18:56

OEIS Server: https://oeis.org/edit/global/285

#2 by N. J. A. Sloane at Fri May 16 03:00:00 EDT 2003

KEYWORD

nonn,new

nonn

AUTHOR

Clark Kimberling (ck6@cedar.(AT)evansville.edu)

#1 by N. J. A. Sloane at Sat Dec 11 03:00:00 EST 1999

NAME

T(2n-1,n), where T is the array defined in A025564.

DATA

1, 4, 22, 120, 665, 3732, 21153, 120835, 694590, 4013088, 23284424, 135580865, 791862354, 4637009300, 27215510265, 160053426720, 942939231825, 5564024727096, 3878367902380, 194530139772844

OFFSET

1,2

KEYWORD

nonn

AUTHOR

Clark Kimberling (ck6@cedar.evansville.edu)

STATUS

approved