The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A188495

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A188495

Number of permutations p on the set [n] with the properties that abs(p(i)-i) <= 3 for all i, p(1) <= 2, and p(4) >= 2.
(history; published version)

#21 by Bruno Berselli at Wed Jan 06 13:53:40 EST 2016

STATUS

proposed

approved

#20 by Jean-François Alcover at Wed Jan 06 13:18:02 EST 2016

STATUS

editing

proposed

#19 by Jean-François Alcover at Wed Jan 06 13:17:55 EST 2016

MATHEMATICA

a[n_] := Permanent[Table[If[Abs[j - i] < 4 && {i, j} != {3, 1} && {i, j} != {4, 1} && {i, j} != {1, 4}, 1, 0], {i, 1, n}, {j, 1, n}]]; a[1] = 1; Table[an = a[n]; Print["a(", n, ") = ", an]; an, {n, 0, 20}] (* Jean-François Alcover, Jan 06 2016, adapted from Maple *)

STATUS

approved

editing

#18 by Charles R Greathouse IV at Sat Jun 13 00:53:51 EDT 2015

LINKS

<a href="/index/Rec#order_14">Index to sequences with entries for linear recurrences with constant coefficients</a>, signature (2,2,0,10,8,-2,-16,-10,-2,4,2,0,2,1).

Discussion

Sat Jun 13

00:53

OEIS Server: https://oeis.org/edit/global/2439

#17 by Michel Marcus at Sat Dec 13 06:36:41 EST 2014

STATUS

reviewed

approved

#16 by Joerg Arndt at Sat Dec 13 06:08:03 EST 2014

STATUS

proposed

reviewed

#15 by Colin Barker at Sat Dec 13 05:06:00 EST 2014

STATUS

editing

proposed

#14 by Colin Barker at Sat Dec 13 05:05:08 EST 2014

LINKS

<a href="/index/Rec#order_14">Index to sequences with linear recurrences with constant coefficients</a>, signature (2,2,0,10,8,-2,-16,-10,-2,4,2,0,2,1).

FORMULA

G.f.: -x*(x +1)*(x^6 +x^5 -x^4 -x^3 -x^2 -x +1) / ((x -1)*(x^13 +3*x^12 +3*x^11 +5*x^10 +9*x^9 +7*x^8 -3*x^7 -19*x^6 -21*x^5 -13*x^4 -3*x^3 -3*x^2 -x +1)). - Colin Barker, Dec 13 2014

PROG

(PARI) concat(0, Vec(-x*(x +1)*(x^6 +x^5 -x^4 -x^3 -x^2 -x +1) / ((x -1)*(x^13 +3*x^12 +3*x^11 +5*x^10 +9*x^9 +7*x^8 -3*x^7 -19*x^6 -21*x^5 -13*x^4 -3*x^3 -3*x^2 -x +1)) + O(x^100))) \\ Colin Barker, Dec 13 2014

KEYWORD

nonn,changed,easy

STATUS

approved

editing

#13 by Joerg Arndt at Wed Dec 10 01:58:59 EST 2014

STATUS

reviewed

approved

#12 by Michel Marcus at Wed Dec 10 01:21:11 EST 2014

STATUS

proposed

reviewed