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Revision History for A049453

(Underlined text is an addition; strikethrough text is a deletion.)

Showing entries 1-10 | older changes
A049453 Second pentagonal numbers with even index: a(n) = n*(6*n+1).
(history; published version)
#43 by Michel Marcus at Fri Feb 18 05:16:39 EST 2022
STATUS

reviewed

approved

#42 by Hugo Pfoertner at Fri Feb 18 03:35:47 EST 2022
STATUS

proposed

reviewed

#41 by Amiram Eldar at Fri Feb 18 03:28:43 EST 2022
STATUS

editing

proposed

#40 by Amiram Eldar at Fri Feb 18 03:24:52 EST 2022
FORMULA

From Amiram Eldar, Feb 18 2022: (Start)

Sum_{n>=1} 1/a(n) = 6 - sqrt(3)*Pi/2 - 2*log(2) - 3*log(3)/2.

Sum_{n>=1} (-1)^(n+1)/a(n) = Pi + log(2) + sqrt(3)*log(2 + sqrt(3)) - 6. (End)

STATUS

approved

editing

#39 by Alois P. Heinz at Wed Jun 07 23:06:52 EDT 2017
STATUS

proposed

approved

#38 by G. C. Greubel at Wed Jun 07 22:37:09 EDT 2017
STATUS

editing

proposed

#37 by G. C. Greubel at Wed Jun 07 22:36:56 EDT 2017
LINKS

G. C. Greubel, <a href="/A049453/b049453.txt">Table of n, a(n) for n = 0..1000</a>

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

FORMULA

a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - G. C. Greubel, Jun 07 2017

MATHEMATICA

Table[n*(6*n + 1), {n, 0, 50}] (* G. C. Greubel, Jun 07 2017 *)

PROG

(PARI) x='x+O('x^50); concat([0], Vec(x*(7+5*x)/(1-x)^3)) \\ G. C. Greubel, Jun 07 2017

STATUS

approved

editing

#36 by Bruno Berselli at Tue Jul 28 10:09:53 EDT 2015
STATUS

editing

approved

#35 by Bruno Berselli at Tue Jul 28 10:09:50 EDT 2015
CROSSREFS

Cf. A254963 (comment).

STATUS

approved

editing

#34 by Bruno Berselli at Tue Jul 28 10:05:01 EDT 2015
STATUS

editing

approved

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Last modified August 18 13:06 EDT 2024. Contains 375269 sequences. (Running on oeis4.)