The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A131531 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A131531

Period 6: repeat [0, 0, 1, 0, 0, -1].
(history; published version)

#44 by Michael De Vlieger at Thu Mar 28 21:54:46 EDT 2024

STATUS

proposed

approved

#43 by Jon E. Schoenfield at Thu Mar 28 19:53:30 EDT 2024

STATUS

editing

proposed

#42 by Jon E. Schoenfield at Thu Mar 28 19:53:25 EDT 2024

COMMENTS

The main diagonal in this array is A001045; the first super-diagonal superdiagonal is the negated elements of A001045, the second super-diagonal superdiagonal is A078008.

FORMULA

a(n) = (-A057079(n+1) - (-1)^n)/3. - R. J. Mathar, Jun 13 2011

a(n) = -cos(Pi*(n-1)/3)/3 + sin(Pi*(n-1)/3)/sqrt(3) - (-1)^n/3. - R. J. Mathar, Oct 08 2011

a(n) + a(n-3) = 0 for n > 3. - Wesley Ivan Hurt, Jun 20 2016

STATUS

approved

editing

#41 by Joerg Arndt at Tue Dec 12 09:25:08 EST 2023

STATUS

proposed

approved

#40 by Paolo P. Lava at Tue Dec 12 09:22:13 EST 2023

STATUS

editing

proposed

#39 by Paolo P. Lava at Tue Dec 12 09:22:11 EST 2023

FORMULA

a(n) = (1/6)*((-(n mod 6)+((n+1) mod 6)+((n+3) mod 6)-((n+4) mod 6)). - Paolo P. Lava, Aug 28 2007

a(n) = (-1)^(n+1)*(((n+1) mod 3) mod 2). - Paolo P. Lava, Mar 14 2011

STATUS

approved

editing

#38 by Charles R Greathouse IV at Thu Sep 08 08:45:31 EDT 2022

PROG

(MAGMAMagma) &cat[[0, 0, 1, 0, 0, -1]^^20]; // Wesley Ivan Hurt, Jun 20 2016

Discussion

Thu Sep 08

08:45

OEIS Server: https://oeis.org/edit/global/2944

#37 by Michael De Vlieger at Fri May 21 22:09:49 EDT 2021

STATUS

proposed

approved

#36 by Jean-François Alcover at Fri May 21 13:13:06 EDT 2021

STATUS

editing

proposed

#35 by Jean-François Alcover at Fri May 21 13:12:43 EDT 2021

COMMENTS

. -42, 43, -43, 42, -43, -42, 43, ...

STATUS

approved

editing

Discussion

Fri May 21

13:13

Jean-François Alcover: Corrected minor typo in comment