The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A026085

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a(n) = number of (s(0), s(1), ..., s(n)) such that every s(i) is an integer, s(0) = 0, |s(i) - s(i-1)| = 1 for i = 1,2,3; |s(i) - s(i-1)| <= 1 for i >= 4, s(n) = 2. Also a(n) = T(n,n-2), where T is the array defined in A026082.
(history; published version)

#6 by R. J. Mathar at Sun Jun 23 10:21:48 EDT 2013

STATUS

editing

approved

#5 by R. J. Mathar at Sun Jun 23 10:21:41 EDT 2013

FORMULA

Conjecture: (n+2)*a(n) +(-5*n-1)*a(n-1) +4*(n-4)*a(n-2) +8*(n-1)*a(n-3) +(-5*n+34)*a(n-4) +3*(-n+7)*a(n-5)=0. - R. J. Mathar, Jun 23 2013

STATUS

approved

editing

#4 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

#3 by N. J. A. Sloane at Sun Feb 20 03:00:00 EST 2005

CROSSREFS

First differences of A026069.

KEYWORD

nonn,new

nonn

#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

a(n) = number of (s(0), s(1), ..., s(n)) such that every s(i) is an integer, s(0) = 0, |s(i) - s(i-1)| = 1 for i = 1,2,3; |s(i) - s(i-1)| <= 1 for i >= 4, s(n) = 2. Also a(n) = T(n,n-2), where T is the array defined in A026082.

DATA

4, 8, 27, 76, 226, 660, 1939, 5688, 16704, 49072, 144254, 424296, 1248728, 3677184, 10834416, 31939584, 94205772, 277997400, 820747275, 2424232956, 7163519202, 21176638868, 62626464319, 185276853192, 548326714720, 1623325361424

OFFSET

4,1

KEYWORD

nonn

AUTHOR

Clark Kimberling (ck6@cedar.evansville.edu)

STATUS

approved