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Revision History for A087958 (Underlined text is an addition; strikethrough text is a deletion.)

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A087958 a(n) is the square of the n-th partial sum minus the n-th partial sum of the squares, divided by a(n-1), for all n>=1, starting with a(0)=1, a(1)=5.
(history; published version)
#8 by Ray Chandler at Fri Jul 31 12:41:59 EDT 2015
STATUS

editing

approved

#7 by Ray Chandler at Fri Jul 31 12:41:55 EDT 2015
LINKS

<a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1, 3, -1).

STATUS

approved

editing

#6 by Charles R Greathouse IV at Thu Nov 21 12:48:13 EST 2013
MATHEMATICA

Join[{1}, LinearRecurrence[{1, 3, -1}, {5, 2, 17}, 30]] (* From ]] (* _Harvey P. Dale, _, Jul 07 2011 *)

Discussion
Thu Nov 21 12:48
OEIS Server: https://oeis.org/edit/global/2062
#5 by Russ Cox at Fri Mar 30 18:36:39 EDT 2012
AUTHOR

_Paul D. Hanna (pauldhanna(AT)juno.com), _, Sep 16 2003

Discussion
Fri Mar 30 18:36
OEIS Server: https://oeis.org/edit/global/213
#4 by Harvey P. Dale at Thu Jul 07 12:45:55 EDT 2011
STATUS

proposed

approved

#3 by Harvey P. Dale at Thu Jul 07 12:45:46 EDT 2011
MATHEMATICA

Join[{1}, LinearRecurrence[{1, 3, -1}, {5, 2, 17}, 30]] (* From Harvey P. Dale, Jul 07 2011 *)

STATUS

approved

proposed

#2 by N. J. A. Sloane at Sat Nov 10 03:00:00 EST 2007
KEYWORD

nonn,new

nonn

AUTHOR

Paul D . Hanna (pauldhanna(AT)juno.com), Sep 16 2003

#1 by N. J. A. Sloane at Thu Feb 19 03:00:00 EST 2004
NAME

a(n) is the square of the n-th partial sum minus the n-th partial sum of the squares, divided by a(n-1), for all n>=1, starting with a(0)=1, a(1)=5.

DATA

1, 5, 2, 17, 18, 67, 104, 287, 532, 1289, 2598, 5933, 12438, 27639, 59020, 129499, 278920, 608397, 1315658, 2861929, 6200506, 13470635, 29210224, 63421623, 137581660, 298636305, 647959662, 1406286917, 3051529598, 6622430687

OFFSET

0,2

FORMULA

a(n) = a(n-1) + 3a(n-2) - a(n-3) for n>3; G.f.: (1+4x-6x^2+x^3)/(1-x-3x^2+x^3).

EXAMPLE

a(4)=18 since ((1+5+2+17)^2 - (1^2+5^2+2^2+17^2))/17 = (25^2-217)/17 = 18.

PROG

(PARI) a(0)=1; a(1)=5; for(n=2, 50, a(n)=((sum(k=0, n, a(k))^2-sum(k=0, n, a(k)^2))/a(n-1))

CROSSREFS

Cf. A087640, A087955, A087956, A087957.

KEYWORD

nonn

AUTHOR

Paul D Hanna (pauldhanna(AT)juno.com), Sep 16 2003

STATUS

approved

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Last modified August 31 06:39 EDT 2024. Contains 375552 sequences. (Running on oeis4.)