The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A284968 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A284968

Least hairpin family matchings with n edges that are both L&P and C&C whose leftmost edge is part of a hairpin.
(history; published version)

#46 by Joerg Arndt at Sat May 02 05:28:43 EDT 2020

STATUS

reviewed

approved

#45 by Michel Marcus at Sat May 02 04:51:06 EDT 2020

STATUS

proposed

reviewed

#44 by F. Chapoton at Sat May 02 04:19:35 EDT 2020

STATUS

editing

proposed

#43 by F. Chapoton at Sat May 02 04:19:27 EDT 2020

PROG

def a(n): return sum([catalan(k) for k in range(1, n + 1)]) - n

print map([a, (n) for n in range(1, 51)]) # Indranil Ghosh, Jul 31 2017

STATUS

approved

editing

Discussion

Sat May 02

04:19

F. Chapoton: adapt to python3, tested

#42 by N. J. A. Sloane at Thu Jan 30 21:29:18 EST 2020

FORMULA

D-finite with recurrence: (n-2)*(n+1)*a(n) = 2*(3*n^2 - 6*n + 1)*a(n-1) - (3*n - 5)*(3*n - 2)*a(n-2) + 2*(n-1)*(2*n - 3)*a(n-3).

Discussion

Thu Jan 30

21:29

OEIS Server: https://oeis.org/edit/global/2847

#41 by R. J. Mathar at Mon Jan 27 12:01:23 EST 2020

STATUS

editing

approved

#40 by R. J. Mathar at Mon Jan 27 12:01:20 EST 2020

FORMULA

RecurrenceD-finite: (n-2)*(n+1)*a(n) = 2*(3*n^2 - 6*n + 1)*a(n-1) - (3*n - 5)*(3*n - 2)*a(n-2) + 2*(n-1)*(2*n - 3)*a(n-3).

STATUS

approved

editing

#39 by N. J. A. Sloane at Sat Dec 07 12:33:53 EST 2019

PROG

print map(a, xrangerange(1, 51)) # Indranil Ghosh, Jul 31 2017

Discussion

Sat Dec 07

12:33

OEIS Server: https://oeis.org/edit/global/2838

#38 by N. J. A. Sloane at Sat Dec 07 12:18:29 EST 2019

PROG

def a(n): return sum([catalan(k) for k in xrangerange(1, n + 1)]) - n

Discussion

Sat Dec 07

12:18

OEIS Server: https://oeis.org/edit/global/2837

#37 by Bruno Berselli at Tue Aug 01 05:41:17 EDT 2017

STATUS

reviewed

approved