The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A267654 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A267654

Irregular triangle of palindromic subsequences. Every row has 2*n+1 terms. From the second row, there are only two alternated numbers: 2*n+4 and 2*n+2.
(history; published version)

#19 by Olivier Gérard at Fri Mar 04 07:25:41 EST 2016

STATUS

proposed

approved

#18 by Michel Marcus at Mon Feb 22 12:23:07 EST 2016

STATUS

editing

proposed

Discussion

Mon Feb 22

13:50

Paul Curtz: Yes. Thanks.

Sun Feb 28

04:03

Paul Curtz: Please,could an editor decide on A267654 and A267942? Thanks.

#17 by Michel Marcus at Mon Feb 22 12:22:52 EST 2016

KEYWORD

nonn,tabf

STATUS

proposed

editing

Discussion

Mon Feb 22

12:23

Michel Marcus: right ?

#16 by Paul Curtz at Wed Jan 20 05:26:12 EST 2016

STATUS

editing

proposed

Discussion

Wed Jan 20

09:02

Michel Marcus: Ah ok, understood.

#15 by Paul Curtz at Wed Jan 20 05:22:34 EST 2016

FORMULA

a(2n) = 4*n + 2 times 4*n + 2 = 2, 2, 6, 6, 6, 6, 6, 6, 10,....

a(2n+1) = 4*(n+1) times 4*(n+1) = 4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8, 8, 12, ....

STATUS

proposed

editing

Discussion

Wed Jan 20

05:25

Paul Curtz: Clearer. Thanks Michel.

#14 by Michel Marcus at Wed Jan 20 04:58:13 EST 2016

STATUS

editing

proposed

#13 by Michel Marcus at Wed Jan 20 04:56:30 EST 2016

NAME

Irregular triangle of palindromic subsequences. Every row has 2*n+1 terms. From the second row, there are only two alternated numbers: 2*n+4 and 2*n+2.

COMMENTS

2, 4, 2, 4,

6, 4, 6, 4,

6, 8, 6, 8, 6, 8, 6, 8,

STATUS

proposed

editing

Discussion

Wed Jan 20

04:57

Michel Marcus: 4*n + 2 times 4*n + 2 : (4*n+2)^2 ?

04:57

Michel Marcus: 4*(n+1) times 4*(n+1) : (4*(n+1) )^2 ?

#12 by Paul Curtz at Wed Jan 20 03:45:51 EST 2016

STATUS

editing

proposed

#11 by Paul Curtz at Wed Jan 20 03:41:24 EST 2016

COMMENTS

a(n) other writing (by pairs):

2, 4, 2, 4,

6, 4, 6, 4,

6, 8, 6, 8, 6, 8, 6, 8,

10 8, 10, 8, 10, 8, 10, 8,

10, 12, 10, 12, 10, 12, 10, 12, 10, 12, 10, 12,

14, 12, 14, 12, 14, 12, 14, 12, 14, 12, 14, 12,

etc.

First column: A168276(n+2). Second column: A168273(n+2).

Row sums: 12, 20, 56, 72, ... = 4*A074378(n+1).

The last term of the successive rows is the number of their terms.

Main diagonal: A005843(n+1).

CROSSREFS

Cf. A007395, A005843, A086520, A008586, A016825, A053186, A069894, A074378, A086520, A168273, A168276, A265667, A265672, A265734.

KEYWORD

nonn,changed,new

STATUS

proposed

editing

#10 by Paul Curtz at Tue Jan 19 11:41:34 EST 2016

STATUS

editing

proposed