The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A332578 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A332578

Number of compositions of n whose negation is unimodal.
(history; published version)

#18 by OEIS Server at Sun Mar 01 05:40:27 EST 2020

LINKS

Vaclav Kotesovec, <a href="/A332578/b332578_1.txt">Table of n, a(n) for n = 0..3000</a> (terms 0..1000 from Andrew Howroyd)

#17 by Vaclav Kotesovec at Sun Mar 01 05:40:27 EST 2020

STATUS

editing

approved

Discussion

Sun Mar 01

05:40

OEIS Server: Installed new b-file as b332578.txt.  Old b-file is now b332578_1.txt.

#16 by Vaclav Kotesovec at Sun Mar 01 05:40:18 EST 2020

LINKS

Andrew Howroyd, Vaclav Kotesovec, <a href="/A332578/b332578_1.txt">Table of n, a(n) for n = 0..3000</a> (terms 0..1000</a> from Andrew Howroyd)

#15 by Vaclav Kotesovec at Sun Mar 01 04:48:05 EST 2020

FORMULA

a(n) ~ Pi * exp(2*Pi*sqrt(n/3)) / (4 * 3^(5/4) * n^(7/4)). - Vaclav Kotesovec, Mar 01 2020

STATUS

approved

editing

#14 by Vaclav Kotesovec at Sun Mar 01 04:09:27 EST 2020

STATUS

editing

approved

#13 by Vaclav Kotesovec at Sun Mar 01 04:08:59 EST 2020

MATHEMATICA

nmax = 50; CoefficientList[Series[1 + Sum[x^j*(1 - x^j)/Product[1 - x^k, {k, j, nmax - j}]^2, {j, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Mar 01 2020 *)

STATUS

approved

editing

#12 by Vaclav Kotesovec at Sun Mar 01 03:21:46 EST 2020

STATUS

reviewed

approved

#11 by Joerg Arndt at Sun Mar 01 01:59:57 EST 2020

STATUS

proposed

reviewed

Discussion

Sun Mar 01

03:12

Vaclav Kotesovec: You can extend also A332669.

#10 by Andrew Howroyd at Sun Mar 01 00:49:35 EST 2020

STATUS

editing

proposed

#9 by Andrew Howroyd at Sun Mar 01 00:49:12 EST 2020

FORMULA

G.f.: 1 + Sum_{j>0} x^j/((1 - x^j)*(Product_{k>j} 1 - x^k)^2). - Andrew Howroyd, Mar 01 2020