The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A002630 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A002630

Number of permutations of length n with two 3-sequences.
(history; published version)

#25 by Alois P. Heinz at Mon May 06 08:23:22 EDT 2024

STATUS

editing

approved

#24 by Alois P. Heinz at Mon May 06 08:23:13 EDT 2024

DATA

0, 0, 0, 1, 2, 12, 71, 481, 3708, 32028, 306723, 3228804, 37080394, 461569226, 6192527700, 89102492915, 1369014167140, 22373840093040, 387602212164321, 7095737193164187, 136885937242792752, 2775675888994318366, 59023506305591628101, 1313445236142071926488

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reviewed

editing

#23 by Amiram Eldar at Mon May 06 07:01:58 EDT 2024

STATUS

proposed

reviewed

#22 by Jean-François Alcover at Mon May 06 06:06:08 EDT 2024

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editing

proposed

#21 by Jean-François Alcover at Mon May 06 06:05:55 EDT 2024

MATHEMATICA

nmax = 22;

CoefficientList[Sum[((m + 2)*(m + 1)*(m + 2)!/2*(x^6*(1 - x)^4/(1 - x^3)^4) + (m + 1)*(m + 1)!*(x^4*(1 + x)*(1 - x)^3)/(1 - x^3)^3)*((x - x^3)/(1 - x^3))^m, {m, 0, nmax}]/x + O[x]^nmax, x] (* Jean-François Alcover, May 06 2024, after Tani Akinari *)

STATUS

approved

editing

#20 by N. J. A. Sloane at Sat Nov 08 14:49:41 EST 2014

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reviewed

approved

#19 by Michel Marcus at Sat Nov 08 09:42:14 EST 2014

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proposed

reviewed

#18 by Jon E. Schoenfield at Sat Nov 08 08:35:43 EST 2014

STATUS

editing

proposed

#17 by Jon E. Schoenfield at Sat Nov 08 08:35:40 EST 2014

AUTHOR

N. J. A. Sloane.

STATUS

proposed

editing

#16 by Michel Marcus at Sat Nov 08 07:42:35 EST 2014

STATUS

editing

proposed